launcher: bump version for new release

Change-Id: Ie0abee81e86046f412b42f08100041cfd3689c4a Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/292682 Reviewed-by: Michael Mortensen <mmortensen@google.com> Tested-by: Mike Frysinger <vapier@google.com>
Fix bug in git trace2 event Write() function when no config present.
2025-06-26 20:17:52 +00:00 · 2021-01-07 22:44:53 +00:00 · 2021-01-07 14:31:51 +00:00 · 2021-01-06 18:53:58 +00:00 · 2021-01-06 18:53:05 +00:00 · 2021-01-06 17:56:51 +00:00
72 changed files with 1829 additions and 1051 deletions
--- a/.github/workflows/test-ci.yml
+++ b/.github/workflows/test-ci.yml
@ -5,7 +5,7 @@ name: Test CI

 on:
  push:
-    branches: [master, repo-1, stable, maint]
+    branches: [main, repo-1, stable, maint]
    tags: [v*]

 jobs:
@ -14,10 +14,7 @@ jobs:
      fail-fast: false
      matrix:
        os: [ubuntu-latest, macos-latest, windows-latest]
-        python-version: [2.7, 3.6, 3.7, 3.8]
-        exclude:
-          - os: windows-latest
-            python-version: 2.7
+        python-version: [3.6, 3.7, 3.8]
    runs-on: ${{ matrix.os }}

    steps:
--- a/.gitignore
+++ b/.gitignore
@ -7,6 +7,7 @@ __pycache__
 .repopickle_*
 /repoc
 /.tox
+/.venv

 # PyCharm related
 /.idea/
--- a/SUBMITTING_PATCHES.md
+++ b/SUBMITTING_PATCHES.md
@ -10,7 +10,7 @@
 - Make corrections if requested.
 - Verify your changes on gerrit so they can be submitted.

-   `git push https://gerrit-review.googlesource.com/git-repo HEAD:refs/for/master`
+   `git push https://gerrit-review.googlesource.com/git-repo HEAD:refs/for/main`


 # Long Version
@ -150,7 +150,7 @@ Push your patches over HTTPS to the review server, possibly through
 a remembered remote to make this easier in the future:

    git config remote.review.url https://gerrit-review.googlesource.com/git-repo
-    git config remote.review.push HEAD:refs/for/master
+    git config remote.review.push HEAD:refs/for/main

    git push review

--- a/color.py
+++ b/color.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
--- a/command.py
+++ b/command.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
--- a/docs/internal-fs-layout.md
+++ b/docs/internal-fs-layout.md
@ -106,7 +106,7 @@ support, see the [manifest-format.md] file.
    setting in the manifest (i.e. the path on the remote server) with a `.git`
    suffix.  This allows for multiple checkouts of the same remote git repo to
    share their objects.  For example, you could have different branches of
-    `foo/bar.git` checked out to `foo/bar-master`, `foo/bar-release`, etc...
+    `foo/bar.git` checked out to `foo/bar-main`, `foo/bar-release`, etc...
    There will be multiple trees under `projects/` for each one, but only one
    under `project-objects/`.

@ -134,6 +134,7 @@ User controlled settings are initialized when running `repo init`.
 |-------------------|---------------------------|-------------|
 | manifest.groups   | `--groups` & `--platform` | The manifest groups to sync |
 | repo.archive      | `--archive`               | Use `git archive` for checkouts |
+| repo.clonebundle  | `--clone-bundle`          | Whether the initial sync used clone.bundle explicitly |
 | repo.clonefilter  | `--clone-filter`          | Filter setting when using [partial git clones] |
 | repo.depth        | `--depth`                 | Create shallow checkouts when cloning |
 | repo.dissociate   | `--dissociate`            | Dissociate from any reference/mirrors after initial clone |
--- a/docs/manifest-format.md
+++ b/docs/manifest-format.md
@ -99,7 +99,8 @@ following DTD:
  <!ATTLIST repo-hooks enabled-list CDATA #REQUIRED>

  <!ELEMENT include EMPTY>
-  <!ATTLIST include name CDATA #REQUIRED>
+  <!ATTLIST include name   CDATA #REQUIRED>
+  <!ATTLIST include groups CDATA #IMPLIED>
 ]>
 ```

@ -110,6 +111,10 @@ A description of the elements and their attributes follows.

 The root element of the file.

+### Element notice
+
+Arbitrary text that is displayed to users whenever `repo sync` finishes.
+The content is simply passed through as it exists in the manifest.

 ### Element remote

@ -142,8 +147,8 @@ Attribute `review`: Hostname of the Gerrit server where reviews
 are uploaded to by `repo upload`.  This attribute is optional;
 if not specified then `repo upload` will not function.

-Attribute `revision`: Name of a Git branch (e.g. `master` or
-`refs/heads/master`). Remotes with their own revision will override
+Attribute `revision`: Name of a Git branch (e.g. `main` or
+`refs/heads/main`). Remotes with their own revision will override
 the default revision.

 ### Element default
@ -156,11 +161,11 @@ Attribute `remote`: Name of a previously defined remote element.
 Project elements lacking a remote attribute of their own will use
 this remote.

-Attribute `revision`: Name of a Git branch (e.g. `master` or
-`refs/heads/master`).  Project elements lacking their own
+Attribute `revision`: Name of a Git branch (e.g. `main` or
+`refs/heads/main`).  Project elements lacking their own
 revision attribute will use this revision.

-Attribute `dest-branch`: Name of a Git branch (e.g. `master`).
+Attribute `dest-branch`: Name of a Git branch (e.g. `main`).
 Project elements not setting their own `dest-branch` will inherit
 this value. If this value is not set, projects will use `revision`
 by default instead.
@ -247,13 +252,13 @@ If not supplied the remote given by the default element is used.

 Attribute `revision`: Name of the Git branch the manifest wants
 to track for this project.  Names can be relative to refs/heads
-(e.g. just "master") or absolute (e.g. "refs/heads/master").
+(e.g. just "main") or absolute (e.g. "refs/heads/main").
 Tags and/or explicit SHA-1s should work in theory, but have not
 been extensively tested.  If not supplied the revision given by
 the remote element is used if applicable, else the default
 element is used.

-Attribute `dest-branch`: Name of a Git branch (e.g. `master`).
+Attribute `dest-branch`: Name of a Git branch (e.g. `main`).
 When using `repo upload`, changes will be submitted for code
 review on this branch. If unspecified both here and in the
 default element, `revision` is used instead.
@ -262,7 +267,7 @@ Attribute `groups`: List of groups to which this project belongs,
 whitespace or comma separated.  All projects belong to the group
 "all", and each project automatically belongs to a group of
 its name:`name` and path:`path`.  E.g. for
-<project name="monkeys" path="barrel-of"/>, that project
+`<project name="monkeys" path="barrel-of"/>`, that project
 definition is implicitly in the following manifest groups:
 default, name:monkeys, and path:barrel-of.  If you place a project in the
 group "notdefault", it will not be automatically downloaded by repo.
@ -359,6 +364,19 @@ This element is mostly useful in a local manifest file, where
 the user can remove a project, and possibly replace it with their
 own definition.

+### Element repo-hooks
+
+NB: See the [practical documentation](./repo-hooks.md) for using repo hooks.
+
+Only one repo-hooks element may be specified at a time.
+Attempting to redefine it will fail to parse.
+
+Attribute `in-project`: The project where the hooks are defined.  The value
+must match the `name` attribute (**not** the `path` attribute) of a previously
+defined `project` element.
+
+Attribute `enabled-list`: List of hooks to use, whitespace or comma separated.
+
 ### Element include

 This element provides the capability of including another manifest
@ -368,6 +386,10 @@ target manifest to include - it must be a usable manifest on its own.
 Attribute `name`: the manifest to include, specified relative to
 the manifest repository's root.

+Attribute `groups`: List of additional groups to which all projects
+in the included manifest belong. This appends and recurses, meaning
+all projects in sub-manifests carry all parent include groups.
+Same syntax as the corresponding element of `project`.

 ## Local Manifests

@ -396,10 +418,4 @@ these extra projects.
 Manifest files stored in `$TOP_DIR/.repo/local_manifests/*.xml` will
 be loaded in alphabetical order.

-Additional remotes and projects may also be added through a local
-manifest, stored in `$TOP_DIR/.repo/local_manifest.xml`. This method
-is deprecated in favor of using multiple manifest files as mentioned
-above.
-
-If `$TOP_DIR/.repo/local_manifest.xml` exists, it will be loaded before
-any manifest files stored in `$TOP_DIR/.repo/local_manifests/*.xml`.
+The legacy `$TOP_DIR/.repo/local_manifest.xml` path is no longer supported.
--- a/docs/python-support.md
+++ b/docs/python-support.md
@ -18,13 +18,13 @@ Bugfixes may be added on a best-effort basis or from the community, but largely
 no new features will be added, nor is support guaranteed.

 Users can select this during `repo init` time via the [repo launcher].
-Otherwise the default branches (e.g. stable & master) will be used which will
+Otherwise the default branches (e.g. stable & main) will be used which will
 require Python 3.

 This means the [repo launcher] needs to support both Python 2 & Python 3, but
 since it doesn't import any other repo code, this shouldn't be too problematic.

-The master branch will require Python 3.6 at a minimum.
+The main branch will require Python 3.6 at a minimum.
 If the system has an older version of Python 3, then users will have to select
 the legacy Python 2 branch instead.

--- a/docs/release-process.md
+++ b/docs/release-process.md
@ -5,6 +5,37 @@ related topics and flows.

 [TOC]

+## Schedule
+
+There is no specific schedule for when releases are made.
+Usually it's more along the lines of "enough minor changes have been merged",
+or "there's a known issue the maintainers know should get fixed".
+If you find a fix has been merged for an issue important to you, but hasn't been
+released after a week or so, feel free to [contact] us to request a new release.
+
+### Release Freezes {#freeze}
+
+We try to observe a regular schedule for when **not** to release.
+If something goes wrong, staff need to be active in order to respond quickly &
+effectively.
+We also don't want to disrupt non-Google organizations if possible.
+
+We generally follow the rules:
+
+* Release during Mon - Thu, 9:00 - 14:00 [US PT]
+* Avoid holidays
+  * All regular [US holidays]
+  * Large international ones if possible
+  * All the various [New Years]
+    * Jan 1 in Gregorian calendar is the most obvious
+    * Check for large Lunar New Years too
+* Follow the normal [Google production freeze schedule]
+
+[US holidays]: https://en.wikipedia.org/wiki/Federal_holidays_in_the_United_States
+[US PT]: https://en.wikipedia.org/wiki/Pacific_Time_Zone
+[New Years]: https://en.wikipedia.org/wiki/New_Year
+[Google production freeze schedule]: http://goto.google.com/prod-freeze
+
 ## Launcher script

 The main repo script serves as a standalone program and is often referred to as
@ -66,7 +97,7 @@ If that tag cannot be verified, it gives up and forces the user to resolve.

 ## Branch management

-All development happens on the `master` branch and should generally be stable.
+All development happens on the `main` branch and should generally be stable.

 Since the repo launcher defaults to tracking the `stable` branch, it is not
 normally updated until a new release is available.
@ -81,7 +112,7 @@ For example, when `stable` moves from `v1.10.x` to `v1.11.x`, then the `maint`
 branch will be updated from `v1.9.x` to `v1.10.x`.

 We don't have parallel release branches/series.
-Typically all tags are made against the `master` branch and then pushed to the
+Typically all tags are made against the `main` branch and then pushed to the
 `stable` branch to make it available to the rest of the world.
 Since repo doesn't typically see a lot of changes, this tends to be OK.

@ -89,10 +120,10 @@ Since repo doesn't typically see a lot of changes, this tends to be OK.

 When you want to create a new release, you'll need to select a good version and
 create a signed tag using a key registered in repo itself.
-Typically we just tag the latest version of the `master` branch.
+Typically we just tag the latest version of the `main` branch.
 The tag could be pushed now, but it won't be used by clients normally (since the
 default `repo-rev` setting is `stable`).
-This would allow some early testing on systems who explicitly select `master`.
+This would allow some early testing on systems who explicitly select `main`.

 ### Creating a signed tag

@ -113,7 +144,7 @@ $ export GNUPGHOME=~/.gnupg/repo/
 $ gpg -K

 # Pick whatever branch or commit you want to tag.
-$ r=master
+$ r=main

 # Pick the new version.
 $ t=1.12.10
@ -242,6 +273,7 @@ Things in italics are things we used to care about but probably don't anymore.
 | Apr 2020 | **Apr 2030** |              |                 | **20.04 Focal**      | 2.25.0   | 2.7.17 3.7.5 |


+[contact]: ../README.md#contact
 [rel-d]: https://en.wikipedia.org/wiki/Debian_version_history
 [rel-g]: https://en.wikipedia.org/wiki/Git#Releases
 [rel-p]: https://en.wikipedia.org/wiki/History_of_Python#Table_of_versions
--- a/docs/repo-hooks.md
+++ b/docs/repo-hooks.md
@ -27,7 +27,7 @@ repohooks project is updated and a hook is triggered.
 For the full syntax, see the [repo manifest format](./manifest-format.md).

 Here's a short example from
-[Android](https://android.googlesource.com/platform/manifest/+/master/default.xml).
+[Android](https://android.googlesource.com/platform/manifest/+/HEAD/default.xml).
 The `<project>` line checks out the repohooks git repo to the local
 `tools/repohooks/` path.  The `<repo-hooks>` line says to look in the project
 with the name `platform/tools/repohooks` for hooks to run during the
--- a/editor.py
+++ b/editor.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 import os
 import re
 import sys
--- a/error.py
+++ b/error.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
--- a/event_log.py
+++ b/event_log.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2017 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,8 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
-
 import json
 import multiprocessing

--- a/git_command.py
+++ b/git_command.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 import os
 import re
 import sys
--- a/git_config.py
+++ b/git_config.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,10 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
-
 import contextlib
 import errno
+from http.client import HTTPException
 import json
 import os
 import re
@ -30,25 +27,12 @@ try:
 except ImportError:
  import dummy_threading as _threading
 import time
-
-from pyversion import is_python3
-if is_python3():
-  import urllib.request
-  import urllib.error
-else:
-  import urllib2
-  import imp
-  urllib = imp.new_module('urllib')
-  urllib.request = urllib2
-  urllib.error = urllib2
+import urllib.error
+import urllib.request

 from error import GitError, UploadError
 import platform_utils
 from repo_trace import Trace
-if is_python3():
-  from http.client import HTTPException
-else:
-  from httplib import HTTPException

 from git_command import GitCommand
 from git_command import ssh_sock
@ -345,8 +329,6 @@ class GitConfig(object):
    d = self._do('--null', '--list')
    if d is None:
      return c
-    if not is_python3():
-      d = d.decode('utf-8')
    for line in d.rstrip('\0').split('\0'):
      if '\n' in line:
        key, val = line.split('\n', 1)
@ -362,7 +344,7 @@ class GitConfig(object):
    return c

  def _do(self, *args):
-    command = ['config', '--file', self.file]
+    command = ['config', '--file', self.file, '--includes']
    command.extend(args)

    p = GitCommand(None,
--- a/git_refs.py
+++ b/git_refs.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2009 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
--- a/git_trace2_event_log.py
+++ b/git_trace2_event_log.py
@ -0,0 +1,211 @@
+# Copyright (C) 2020 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Provide event logging in the git trace2 EVENT format.
+
+The git trace2 EVENT format is defined at:
+https://www.kernel.org/pub/software/scm/git/docs/technical/api-trace2.html#_event_format
+https://git-scm.com/docs/api-trace2#_the_event_format_target
+
+  Usage:
+
+  git_trace_log = EventLog()
+  git_trace_log.StartEvent()
+  ...
+  git_trace_log.ExitEvent()
+  git_trace_log.Write()
+"""
+
+
+import datetime
+import json
+import os
+import sys
+import tempfile
+import threading
+
+from git_command import GitCommand, RepoSourceVersion
+
+
+class EventLog(object):
+  """Event log that records events that occurred during a repo invocation.
+
+  Events are written to the log as a consecutive JSON entries, one per line.
+  Entries follow the git trace2 EVENT format.
+
+  Each entry contains the following common keys:
+  - event: The event name
+  - sid: session-id - Unique string to allow process instance to be identified.
+  - thread: The thread name.
+  - time: is the UTC time of the event.
+
+  Valid 'event' names and event specific fields are documented here:
+  https://git-scm.com/docs/api-trace2#_event_format
+  """
+
+  def __init__(self, env=None):
+    """Initializes the event log."""
+    self._log = []
+    # Try to get session-id (sid) from environment (setup in repo launcher).
+    KEY = 'GIT_TRACE2_PARENT_SID'
+    if env is None:
+      env = os.environ
+
+    now = datetime.datetime.utcnow()
+
+    # Save both our sid component and the complete sid.
+    # We use our sid component (self._sid) as the unique filename prefix and
+    # the full sid (self._full_sid) in the log itself.
+    self._sid = 'repo-%s-P%08x' % (now.strftime('%Y%m%dT%H%M%SZ'), os.getpid())
+    parent_sid = env.get(KEY)
+    # Append our sid component to the parent sid (if it exists).
+    if parent_sid is not None:
+      self._full_sid = parent_sid + '/' + self._sid
+    else:
+      self._full_sid = self._sid
+
+    # Set/update the environment variable.
+    # Environment handling across systems is messy.
+    try:
+      env[KEY] = self._full_sid
+    except UnicodeEncodeError:
+      env[KEY] = self._full_sid.encode()
+
+    # Add a version event to front of the log.
+    self._AddVersionEvent()
+
+  @property
+  def full_sid(self):
+    return self._full_sid
+
+  def _AddVersionEvent(self):
+    """Adds a 'version' event at the beginning of current log."""
+    version_event = self._CreateEventDict('version')
+    version_event['evt'] = 2
+    version_event['exe'] = RepoSourceVersion()
+    self._log.insert(0, version_event)
+
+  def _CreateEventDict(self, event_name):
+    """Returns a dictionary with the common keys/values for git trace2 events.
+
+    Args:
+      event_name: The event name.
+
+    Returns:
+      Dictionary with the common event fields populated.
+    """
+    return {
+        'event': event_name,
+        'sid': self._full_sid,
+        'thread': threading.currentThread().getName(),
+        'time': datetime.datetime.utcnow().isoformat() + 'Z',
+    }
+
+  def StartEvent(self):
+    """Append a 'start' event to the current log."""
+    start_event = self._CreateEventDict('start')
+    start_event['argv'] = sys.argv
+    self._log.append(start_event)
+
+  def ExitEvent(self, result):
+    """Append an 'exit' event to the current log.
+
+    Args:
+      result: Exit code of the event
+    """
+    exit_event = self._CreateEventDict('exit')
+
+    # Consider 'None' success (consistent with event_log result handling).
+    if result is None:
+      result = 0
+    exit_event['code'] = result
+    self._log.append(exit_event)
+
+  def _GetEventTargetPath(self):
+    """Get the 'trace2.eventtarget' path from git configuration.
+
+    Returns:
+      path: git config's 'trace2.eventtarget' path if it exists, or None
+    """
+    path = None
+    cmd = ['config', '--get', 'trace2.eventtarget']
+    # TODO(https://crbug.com/gerrit/13706): Use GitConfig when it supports
+    # system git config variables.
+    p = GitCommand(None, cmd, capture_stdout=True, capture_stderr=True,
+                   bare=True)
+    retval = p.Wait()
+    if retval == 0:
+      # Strip trailing carriage-return in path.
+      path = p.stdout.rstrip('\n')
+    elif retval != 1:
+      # `git config --get` is documented to produce an exit status of `1` if
+      # the requested variable is not present in the configuration. Report any
+      # other return value as an error.
+      print("repo: error: 'git config --get' call failed with return code: %r, stderr: %r" % (
+          retval, p.stderr), file=sys.stderr)
+    return path
+
+  def Write(self, path=None):
+    """Writes the log out to a file.
+
+    Log is only written if 'path' or 'git config --get trace2.eventtarget'
+    provide a valid path to write logs to.
+
+    Logging filename format follows the git trace2 style of being a unique
+    (exclusive writable) file.
+
+    Args:
+      path: Path to where logs should be written.
+
+    Returns:
+      log_path: Path to the log file if log is written, otherwise None
+    """
+    log_path = None
+    # If no logging path is specified, get the path from 'trace2.eventtarget'.
+    if path is None:
+      path = self._GetEventTargetPath()
+
+    # If no logging path is specified, exit.
+    if path is None:
+      return None
+
+    if isinstance(path, str):
+      # Get absolute path.
+      path = os.path.abspath(os.path.expanduser(path))
+    else:
+      raise TypeError('path: str required but got %s.' % type(path))
+
+    # Git trace2 requires a directory to write log to.
+
+    # TODO(https://crbug.com/gerrit/13706): Support file (append) mode also.
+    if not os.path.isdir(path):
+      return None
+    # Use NamedTemporaryFile to generate a unique filename as required by git trace2.
+    try:
+      with tempfile.NamedTemporaryFile(mode='x', prefix=self._sid, dir=path,
+                                       delete=False) as f:
+        # TODO(https://crbug.com/gerrit/13706): Support writing events as they
+        # occur.
+        for e in self._log:
+          # Dump in compact encoding mode.
+          # See 'Compact encoding' in Python docs:
+          # https://docs.python.org/3/library/json.html#module-json
+          json.dump(e, f, indent=None, separators=(',', ':'))
+          f.write('\n')
+        log_path = f.name
+    except FileExistsError as err:
+      print('repo: warning: git trace2 logging failed: %r' % err,
+            file=sys.stderr)
+      return None
+    return log_path
--- a/gitc_utils.py
+++ b/gitc_utils.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2015 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 import os
 import platform
 import re
@ -45,7 +42,8 @@ def _set_project_revisions(projects):
  should not be overly large. Recommend calling this function multiple times
  with each call not exceeding NUM_BATCH_RETRIEVE_REVISIONID projects.

-  @param projects: List of project objects to set the revionExpr for.
+  Args:
+    projects: List of project objects to set the revionExpr for.
  """
  # Retrieve the commit id for each project based off of it's current
  # revisionExpr and it is not already a commit id.
@ -73,7 +71,8 @@ def _manifest_groups(manifest):
  This is the same logic used by Command.GetProjects(), which is used during
  repo sync

-  @param manifest: The XmlManifest object
+  Args:
+    manifest: The XmlManifest object
  """
  mp = manifest.manifestProject
  groups = mp.config.GetString('manifest.groups')
@ -85,9 +84,10 @@ def _manifest_groups(manifest):
 def generate_gitc_manifest(gitc_manifest, manifest, paths=None):
  """Generate a manifest for shafsd to use for this GITC client.

-  @param gitc_manifest: Current gitc manifest, or None if there isn't one yet.
-  @param manifest: A GitcManifest object loaded with the current repo manifest.
-  @param paths: List of project paths we want to update.
+  Args:
+    gitc_manifest: Current gitc manifest, or None if there isn't one yet.
+    manifest: A GitcManifest object loaded with the current repo manifest.
+    paths: List of project paths we want to update.
  """

  print('Generating GITC Manifest by fetching revision SHAs for each '
@ -149,12 +149,15 @@ def generate_gitc_manifest(gitc_manifest, manifest, paths=None):
 def save_manifest(manifest, client_dir=None):
  """Save the manifest file in the client_dir.

-  @param client_dir: Client directory to save the manifest in.
-  @param manifest: Manifest object to save.
+  Args:
+    manifest: Manifest object to save.
+    client_dir: Client directory to save the manifest in.
  """
  if not client_dir:
-    client_dir = manifest.gitc_client_dir
-  with open(os.path.join(client_dir, '.manifest'), 'w') as f:
+    manifest_file = manifest.manifestFile
+  else:
+    manifest_file = os.path.join(client_dir, '.manifest')
+  with open(manifest_file, 'w') as f:
    manifest.Save(f, groups=_manifest_groups(manifest))
  # TODO(sbasi/jorg): Come up with a solution to remove the sleep below.
  # Give the GITC filesystem time to register the manifest changes.
--- a/hooks.py
+++ b/hooks.py
@ -0,0 +1,509 @@
+# Copyright (C) 2008 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import errno
+import json
+import os
+import re
+import subprocess
+import sys
+import traceback
+import urllib.parse
+
+from error import HookError
+from git_refs import HEAD
+
+
+class RepoHook(object):
+  """A RepoHook contains information about a script to run as a hook.
+
+  Hooks are used to run a python script before running an upload (for instance,
+  to run presubmit checks).  Eventually, we may have hooks for other actions.
+
+  This shouldn't be confused with files in the 'repo/hooks' directory.  Those
+  files are copied into each '.git/hooks' folder for each project.  Repo-level
+  hooks are associated instead with repo actions.
+
+  Hooks are always python.  When a hook is run, we will load the hook into the
+  interpreter and execute its main() function.
+
+  Combinations of hook option flags:
+  - no-verify=False, verify=False (DEFAULT):
+    If stdout is a tty, can prompt about running hooks if needed.
+    If user denies running hooks, the action is cancelled. If stdout is
+    not a tty and we would need to prompt about hooks, action is
+    cancelled.
+  - no-verify=False, verify=True:
+    Always run hooks with no prompt.
+  - no-verify=True, verify=False:
+    Never run hooks, but run action anyway (AKA bypass hooks).
+  - no-verify=True, verify=True:
+    Invalid
+  """
+
+  def __init__(self,
+               hook_type,
+               hooks_project,
+               repo_topdir,
+               manifest_url,
+               bypass_hooks=False,
+               allow_all_hooks=False,
+               ignore_hooks=False,
+               abort_if_user_denies=False):
+    """RepoHook constructor.
+
+    Params:
+      hook_type: A string representing the type of hook.  This is also used
+          to figure out the name of the file containing the hook.  For
+          example: 'pre-upload'.
+      hooks_project: The project containing the repo hooks.
+          If you have a manifest, this is manifest.repo_hooks_project.
+          OK if this is None, which will make the hook a no-op.
+      repo_topdir: The top directory of the repo client checkout.
+          This is the one containing the .repo directory. Scripts will
+          run with CWD as this directory.
+          If you have a manifest, this is manifest.topdir.
+      manifest_url: The URL to the manifest git repo.
+      bypass_hooks: If True, then 'Do not run the hook'.
+      allow_all_hooks: If True, then 'Run the hook without prompting'.
+      ignore_hooks: If True, then 'Do not abort action if hooks fail'.
+      abort_if_user_denies: If True, we'll abort running the hook if the user
+          doesn't allow us to run the hook.
+    """
+    self._hook_type = hook_type
+    self._hooks_project = hooks_project
+    self._repo_topdir = repo_topdir
+    self._manifest_url = manifest_url
+    self._bypass_hooks = bypass_hooks
+    self._allow_all_hooks = allow_all_hooks
+    self._ignore_hooks = ignore_hooks
+    self._abort_if_user_denies = abort_if_user_denies
+
+    # Store the full path to the script for convenience.
+    if self._hooks_project:
+      self._script_fullpath = os.path.join(self._hooks_project.worktree,
+                                           self._hook_type + '.py')
+    else:
+      self._script_fullpath = None
+
+  def _GetHash(self):
+    """Return a hash of the contents of the hooks directory.
+
+    We'll just use git to do this.  This hash has the property that if anything
+    changes in the directory we will return a different has.
+
+    SECURITY CONSIDERATION:
+      This hash only represents the contents of files in the hook directory, not
+      any other files imported or called by hooks.  Changes to imported files
+      can change the script behavior without affecting the hash.
+
+    Returns:
+      A string representing the hash.  This will always be ASCII so that it can
+      be printed to the user easily.
+    """
+    assert self._hooks_project, "Must have hooks to calculate their hash."
+
+    # We will use the work_git object rather than just calling GetRevisionId().
+    # That gives us a hash of the latest checked in version of the files that
+    # the user will actually be executing.  Specifically, GetRevisionId()
+    # doesn't appear to change even if a user checks out a different version
+    # of the hooks repo (via git checkout) nor if a user commits their own revs.
+    #
+    # NOTE: Local (non-committed) changes will not be factored into this hash.
+    # I think this is OK, since we're really only worried about warning the user
+    # about upstream changes.
+    return self._hooks_project.work_git.rev_parse(HEAD)
+
+  def _GetMustVerb(self):
+    """Return 'must' if the hook is required; 'should' if not."""
+    if self._abort_if_user_denies:
+      return 'must'
+    else:
+      return 'should'
+
+  def _CheckForHookApproval(self):
+    """Check to see whether this hook has been approved.
+
+    We'll accept approval of manifest URLs if they're using secure transports.
+    This way the user can say they trust the manifest hoster.  For insecure
+    hosts, we fall back to checking the hash of the hooks repo.
+
+    Note that we ask permission for each individual hook even though we use
+    the hash of all hooks when detecting changes.  We'd like the user to be
+    able to approve / deny each hook individually.  We only use the hash of all
+    hooks because there is no other easy way to detect changes to local imports.
+
+    Returns:
+      True if this hook is approved to run; False otherwise.
+
+    Raises:
+      HookError: Raised if the user doesn't approve and abort_if_user_denies
+          was passed to the consturctor.
+    """
+    if self._ManifestUrlHasSecureScheme():
+      return self._CheckForHookApprovalManifest()
+    else:
+      return self._CheckForHookApprovalHash()
+
+  def _CheckForHookApprovalHelper(self, subkey, new_val, main_prompt,
+                                  changed_prompt):
+    """Check for approval for a particular attribute and hook.
+
+    Args:
+      subkey: The git config key under [repo.hooks.<hook_type>] to store the
+          last approved string.
+      new_val: The new value to compare against the last approved one.
+      main_prompt: Message to display to the user to ask for approval.
+      changed_prompt: Message explaining why we're re-asking for approval.
+
+    Returns:
+      True if this hook is approved to run; False otherwise.
+
+    Raises:
+      HookError: Raised if the user doesn't approve and abort_if_user_denies
+          was passed to the consturctor.
+    """
+    hooks_config = self._hooks_project.config
+    git_approval_key = 'repo.hooks.%s.%s' % (self._hook_type, subkey)
+
+    # Get the last value that the user approved for this hook; may be None.
+    old_val = hooks_config.GetString(git_approval_key)
+
+    if old_val is not None:
+      # User previously approved hook and asked not to be prompted again.
+      if new_val == old_val:
+        # Approval matched.  We're done.
+        return True
+      else:
+        # Give the user a reason why we're prompting, since they last told
+        # us to "never ask again".
+        prompt = 'WARNING: %s\n\n' % (changed_prompt,)
+    else:
+      prompt = ''
+
+    # Prompt the user if we're not on a tty; on a tty we'll assume "no".
+    if sys.stdout.isatty():
+      prompt += main_prompt + ' (yes/always/NO)? '
+      response = input(prompt).lower()
+      print()
+
+      # User is doing a one-time approval.
+      if response in ('y', 'yes'):
+        return True
+      elif response == 'always':
+        hooks_config.SetString(git_approval_key, new_val)
+        return True
+
+    # For anything else, we'll assume no approval.
+    if self._abort_if_user_denies:
+      raise HookError('You must allow the %s hook or use --no-verify.' %
+                      self._hook_type)
+
+    return False
+
+  def _ManifestUrlHasSecureScheme(self):
+    """Check if the URI for the manifest is a secure transport."""
+    secure_schemes = ('file', 'https', 'ssh', 'persistent-https', 'sso', 'rpc')
+    parse_results = urllib.parse.urlparse(self._manifest_url)
+    return parse_results.scheme in secure_schemes
+
+  def _CheckForHookApprovalManifest(self):
+    """Check whether the user has approved this manifest host.
+
+    Returns:
+      True if this hook is approved to run; False otherwise.
+    """
+    return self._CheckForHookApprovalHelper(
+        'approvedmanifest',
+        self._manifest_url,
+        'Run hook scripts from %s' % (self._manifest_url,),
+        'Manifest URL has changed since %s was allowed.' % (self._hook_type,))
+
+  def _CheckForHookApprovalHash(self):
+    """Check whether the user has approved the hooks repo.
+
+    Returns:
+      True if this hook is approved to run; False otherwise.
+    """
+    prompt = ('Repo %s run the script:\n'
+              '  %s\n'
+              '\n'
+              'Do you want to allow this script to run')
+    return self._CheckForHookApprovalHelper(
+        'approvedhash',
+        self._GetHash(),
+        prompt % (self._GetMustVerb(), self._script_fullpath),
+        'Scripts have changed since %s was allowed.' % (self._hook_type,))
+
+  @staticmethod
+  def _ExtractInterpFromShebang(data):
+    """Extract the interpreter used in the shebang.
+
+    Try to locate the interpreter the script is using (ignoring `env`).
+
+    Args:
+      data: The file content of the script.
+
+    Returns:
+      The basename of the main script interpreter, or None if a shebang is not
+      used or could not be parsed out.
+    """
+    firstline = data.splitlines()[:1]
+    if not firstline:
+      return None
+
+    # The format here can be tricky.
+    shebang = firstline[0].strip()
+    m = re.match(r'^#!\s*([^\s]+)(?:\s+([^\s]+))?', shebang)
+    if not m:
+      return None
+
+    # If the using `env`, find the target program.
+    interp = m.group(1)
+    if os.path.basename(interp) == 'env':
+      interp = m.group(2)
+
+    return interp
+
+  def _ExecuteHookViaReexec(self, interp, context, **kwargs):
+    """Execute the hook script through |interp|.
+
+    Note: Support for this feature should be dropped ~Jun 2021.
+
+    Args:
+      interp: The Python program to run.
+      context: Basic Python context to execute the hook inside.
+      kwargs: Arbitrary arguments to pass to the hook script.
+
+    Raises:
+      HookError: When the hooks failed for any reason.
+    """
+    # This logic needs to be kept in sync with _ExecuteHookViaImport below.
+    script = """
+import json, os, sys
+path = '''%(path)s'''
+kwargs = json.loads('''%(kwargs)s''')
+context = json.loads('''%(context)s''')
+sys.path.insert(0, os.path.dirname(path))
+data = open(path).read()
+exec(compile(data, path, 'exec'), context)
+context['main'](**kwargs)
+""" % {
+        'path': self._script_fullpath,
+        'kwargs': json.dumps(kwargs),
+        'context': json.dumps(context),
+    }
+
+    # We pass the script via stdin to avoid OS argv limits.  It also makes
+    # unhandled exception tracebacks less verbose/confusing for users.
+    cmd = [interp, '-c', 'import sys; exec(sys.stdin.read())']
+    proc = subprocess.Popen(cmd, stdin=subprocess.PIPE)
+    proc.communicate(input=script.encode('utf-8'))
+    if proc.returncode:
+      raise HookError('Failed to run %s hook.' % (self._hook_type,))
+
+  def _ExecuteHookViaImport(self, data, context, **kwargs):
+    """Execute the hook code in |data| directly.
+
+    Args:
+      data: The code of the hook to execute.
+      context: Basic Python context to execute the hook inside.
+      kwargs: Arbitrary arguments to pass to the hook script.
+
+    Raises:
+      HookError: When the hooks failed for any reason.
+    """
+    # Exec, storing global context in the context dict.  We catch exceptions
+    # and convert to a HookError w/ just the failing traceback.
+    try:
+      exec(compile(data, self._script_fullpath, 'exec'), context)
+    except Exception:
+      raise HookError('%s\nFailed to import %s hook; see traceback above.' %
+                      (traceback.format_exc(), self._hook_type))
+
+    # Running the script should have defined a main() function.
+    if 'main' not in context:
+      raise HookError('Missing main() in: "%s"' % self._script_fullpath)
+
+    # Call the main function in the hook.  If the hook should cause the
+    # build to fail, it will raise an Exception.  We'll catch that convert
+    # to a HookError w/ just the failing traceback.
+    try:
+      context['main'](**kwargs)
+    except Exception:
+      raise HookError('%s\nFailed to run main() for %s hook; see traceback '
+                      'above.' % (traceback.format_exc(), self._hook_type))
+
+  def _ExecuteHook(self, **kwargs):
+    """Actually execute the given hook.
+
+    This will run the hook's 'main' function in our python interpreter.
+
+    Args:
+      kwargs: Keyword arguments to pass to the hook.  These are often specific
+          to the hook type.  For instance, pre-upload hooks will contain
+          a project_list.
+    """
+    # Keep sys.path and CWD stashed away so that we can always restore them
+    # upon function exit.
+    orig_path = os.getcwd()
+    orig_syspath = sys.path
+
+    try:
+      # Always run hooks with CWD as topdir.
+      os.chdir(self._repo_topdir)
+
+      # Put the hook dir as the first item of sys.path so hooks can do
+      # relative imports.  We want to replace the repo dir as [0] so
+      # hooks can't import repo files.
+      sys.path = [os.path.dirname(self._script_fullpath)] + sys.path[1:]
+
+      # Initial global context for the hook to run within.
+      context = {'__file__': self._script_fullpath}
+
+      # Add 'hook_should_take_kwargs' to the arguments to be passed to main.
+      # We don't actually want hooks to define their main with this argument--
+      # it's there to remind them that their hook should always take **kwargs.
+      # For instance, a pre-upload hook should be defined like:
+      #   def main(project_list, **kwargs):
+      #
+      # This allows us to later expand the API without breaking old hooks.
+      kwargs = kwargs.copy()
+      kwargs['hook_should_take_kwargs'] = True
+
+      # See what version of python the hook has been written against.
+      data = open(self._script_fullpath).read()
+      interp = self._ExtractInterpFromShebang(data)
+      reexec = False
+      if interp:
+        prog = os.path.basename(interp)
+        if prog.startswith('python2') and sys.version_info.major != 2:
+          reexec = True
+        elif prog.startswith('python3') and sys.version_info.major == 2:
+          reexec = True
+
+      # Attempt to execute the hooks through the requested version of Python.
+      if reexec:
+        try:
+          self._ExecuteHookViaReexec(interp, context, **kwargs)
+        except OSError as e:
+          if e.errno == errno.ENOENT:
+            # We couldn't find the interpreter, so fallback to importing.
+            reexec = False
+          else:
+            raise
+
+      # Run the hook by importing directly.
+      if not reexec:
+        self._ExecuteHookViaImport(data, context, **kwargs)
+    finally:
+      # Restore sys.path and CWD.
+      sys.path = orig_syspath
+      os.chdir(orig_path)
+
+  def _CheckHook(self):
+    # Bail with a nice error if we can't find the hook.
+    if not os.path.isfile(self._script_fullpath):
+      raise HookError('Couldn\'t find repo hook: %s' % self._script_fullpath)
+
+  def Run(self, **kwargs):
+    """Run the hook.
+
+    If the hook doesn't exist (because there is no hooks project or because
+    this particular hook is not enabled), this is a no-op.
+
+    Args:
+      user_allows_all_hooks: If True, we will never prompt about running the
+          hook--we'll just assume it's OK to run it.
+      kwargs: Keyword arguments to pass to the hook.  These are often specific
+          to the hook type.  For instance, pre-upload hooks will contain
+          a project_list.
+
+    Returns:
+      True: On success or ignore hooks by user-request
+      False: The hook failed. The caller should respond with aborting the action.
+        Some examples in which False is returned:
+        * Finding the hook failed while it was enabled, or
+        * the user declined to run a required hook (from _CheckForHookApproval)
+        In all these cases the user did not pass the proper arguments to
+        ignore the result through the option combinations as listed in
+        AddHookOptionGroup().
+    """
+    # Do not do anything in case bypass_hooks is set, or
+    # no-op if there is no hooks project or if hook is disabled.
+    if (self._bypass_hooks or
+        not self._hooks_project or
+        self._hook_type not in self._hooks_project.enabled_repo_hooks):
+      return True
+
+    passed = True
+    try:
+      self._CheckHook()
+
+      # Make sure the user is OK with running the hook.
+      if self._allow_all_hooks or self._CheckForHookApproval():
+        # Run the hook with the same version of python we're using.
+        self._ExecuteHook(**kwargs)
+    except SystemExit as e:
+      passed = False
+      print('ERROR: %s hooks exited with exit code: %s' % (self._hook_type, str(e)),
+            file=sys.stderr)
+    except HookError as e:
+      passed = False
+      print('ERROR: %s' % str(e), file=sys.stderr)
+
+    if not passed and self._ignore_hooks:
+      print('\nWARNING: %s hooks failed, but continuing anyways.' % self._hook_type,
+            file=sys.stderr)
+      passed = True
+
+    return passed
+
+  @classmethod
+  def FromSubcmd(cls, manifest, opt, *args, **kwargs):
+    """Method to construct the repo hook class
+
+    Args:
+      manifest: The current active manifest for this command from which we
+          extract a couple of fields.
+      opt: Contains the commandline options for the action of this hook.
+          It should contain the options added by AddHookOptionGroup() in which
+          we are interested in RepoHook execution.
+    """
+    for key in ('bypass_hooks', 'allow_all_hooks', 'ignore_hooks'):
+      kwargs.setdefault(key, getattr(opt, key))
+    kwargs.update({
+        'hooks_project': manifest.repo_hooks_project,
+        'repo_topdir': manifest.topdir,
+        'manifest_url': manifest.manifestProject.GetRemote('origin').url,
+    })
+    return cls(*args, **kwargs)
+
+  @staticmethod
+  def AddOptionGroup(parser, name):
+    """Help options relating to the various hooks."""
+
+    # Note that verify and no-verify are NOT opposites of each other, which
+    # is why they store to different locations. We are using them to match
+    # 'git commit' syntax.
+    group = parser.add_option_group(name + ' hooks')
+    group.add_option('--no-verify',
+                     dest='bypass_hooks', action='store_true',
+                     help='Do not run the %s hook.' % name)
+    group.add_option('--verify',
+                     dest='allow_all_hooks', action='store_true',
+                     help='Run the %s hook without prompting.' % name)
+    group.add_option('--ignore-hooks',
+                     action='store_true',
+                     help='Do not abort if %s hooks fail.' % name)
--- a/main.py
+++ b/main.py
@ -1,5 +1,4 @@
-#!/usr/bin/env python
-# -*- coding:utf-8 -*-
+#!/usr/bin/env python3
 #
 # Copyright (C) 2008 The Android Open Source Project
 #
@ -21,7 +20,6 @@ People shouldn't run this directly; instead, they should use the `repo` wrapper
 which takes care of execing this entry point.
 """

-from __future__ import print_function
 import getpass
 import netrc
 import optparse
@ -30,15 +28,7 @@ import shlex
 import sys
 import textwrap
 import time
-
-from pyversion import is_python3
-if is_python3():
-  import urllib.request
-else:
-  import imp
-  import urllib2
-  urllib = imp.new_module('urllib')
-  urllib.request = urllib2
+import urllib.request

 try:
  import kerberos
@ -50,6 +40,7 @@ import event_log
 from repo_trace import SetTrace
 from git_command import user_agent
 from git_config import init_ssh, close_ssh, RepoConfig
+from git_trace2_event_log import EventLog
 from command import InteractiveCommand
 from command import MirrorSafeCommand
 from command import GitcAvailableCommand, GitcClientCommand
@ -63,14 +54,12 @@ from error import NoManifestException
 from error import NoSuchProjectError
 from error import RepoChangedException
 import gitc_utils
-from manifest_xml import GitcManifest, XmlManifest
+from manifest_xml import GitcClient, RepoClient
 from pager import RunPager, TerminatePager
 from wrapper import WrapperPath, Wrapper

 from subcmds import all_commands

-if not is_python3():
-  input = raw_input  # noqa: F821

 # NB: These do not need to be kept in sync with the repo launcher script.
 # These may be much newer as it allows the repo launcher to roll between
@ -82,12 +71,13 @@ if not is_python3():
 #
 # python-3.6 is in Ubuntu Bionic.
 MIN_PYTHON_VERSION_SOFT = (3, 6)
-MIN_PYTHON_VERSION_HARD = (3, 4)
+MIN_PYTHON_VERSION_HARD = (3, 5)

 if sys.version_info.major < 3:
-  print('repo: warning: Python 2 is no longer supported; '
+  print('repo: error: Python 2 is no longer supported; '
        'Please upgrade to Python {}.{}+.'.format(*MIN_PYTHON_VERSION_SOFT),
        file=sys.stderr)
+  sys.exit(1)
 else:
  if sys.version_info < MIN_PYTHON_VERSION_HARD:
    print('repo: error: Python 3 version is too old; '
@ -129,6 +119,8 @@ global_options.add_option('--version',
 global_options.add_option('--event-log',
                          dest='event_log', action='store',
                          help='filename of event log to append timeline to')
+global_options.add_option('--git-trace2-event-log', action='store',
+                          help='directory to write git trace2 event log to')


 class _Repo(object):
@ -210,15 +202,17 @@ class _Repo(object):
            file=sys.stderr)
      return 1

+    git_trace2_event_log = EventLog()
    cmd.repodir = self.repodir
-    cmd.manifest = XmlManifest(cmd.repodir)
+    cmd.client = RepoClient(cmd.repodir)
+    cmd.manifest = cmd.client.manifest
    cmd.gitc_manifest = None
    gitc_client_name = gitc_utils.parse_clientdir(os.getcwd())
    if gitc_client_name:
-      cmd.gitc_manifest = GitcManifest(cmd.repodir, gitc_client_name)
-      cmd.manifest.isGitcClient = True
+      cmd.gitc_manifest = GitcClient(cmd.repodir, gitc_client_name)
+      cmd.client.isGitcClient = True

-    Editor.globalConfig = cmd.manifest.globalConfig
+    Editor.globalConfig = cmd.client.globalConfig

    if not isinstance(cmd, MirrorSafeCommand) and cmd.manifest.IsMirror:
      print("fatal: '%s' requires a working directory" % name,
@ -246,7 +240,7 @@ class _Repo(object):
      return 1

    if gopts.pager is not False and not isinstance(cmd, InteractiveCommand):
-      config = cmd.manifest.globalConfig
+      config = cmd.client.globalConfig
      if gopts.pager:
        use_pager = True
      else:
@ -259,6 +253,8 @@ class _Repo(object):
    start = time.time()
    cmd_event = cmd.event_log.Add(name, event_log.TASK_COMMAND, start)
    cmd.event_log.SetParent(cmd_event)
+    git_trace2_event_log.StartEvent()
+
    try:
      cmd.ValidateOptions(copts, cargs)
      result = cmd.Execute(copts, cargs)
@ -301,10 +297,13 @@ class _Repo(object):

      cmd.event_log.FinishEvent(cmd_event, finish,
                                result is None or result == 0)
+      git_trace2_event_log.ExitEvent(result)
+
      if gopts.event_log:
        cmd.event_log.Write(os.path.abspath(
                            os.path.expanduser(gopts.event_log)))

+      git_trace2_event_log.Write(gopts.git_trace2_event_log)
    return result


@ -614,7 +613,7 @@ def _Main(argv):
    argv = list(sys.argv)
    argv.extend(rce.extra_args)
    try:
-      os.execv(__file__, argv)
+      os.execv(sys.executable, [__file__] + argv)
    except OSError as e:
      print('fatal: cannot restart repo after upgrade', file=sys.stderr)
      print('fatal: %s' % e, file=sys.stderr)
--- a/manifest_xml.py
+++ b/manifest_xml.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,24 +12,15 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 import itertools
 import os
 import re
 import sys
 import xml.dom.minidom
-
-from pyversion import is_python3
-if is_python3():
-  import urllib.parse
-else:
-  import imp
-  import urlparse
-  urllib = imp.new_module('urllib')
-  urllib.parse = urlparse
+import urllib.parse

 import gitc_utils
-from git_config import GitConfig
+from git_config import GitConfig, IsId
 from git_refs import R_HEADS, HEAD
 import platform_utils
 from project import RemoteSpec, Project, MetaProject
@ -187,13 +176,24 @@ class _XmlRemote(object):
 class XmlManifest(object):
  """manages the repo configuration file"""

-  def __init__(self, repodir):
+  def __init__(self, repodir, manifest_file, local_manifests=None):
+    """Initialize.
+
+    Args:
+      repodir: Path to the .repo/ dir for holding all internal checkout state.
+          It must be in the top directory of the repo client checkout.
+      manifest_file: Full path to the manifest file to parse.  This will usually
+          be |repodir|/|MANIFEST_FILE_NAME|.
+      local_manifests: Full path to the directory of local override manifests.
+          This will usually be |repodir|/|LOCAL_MANIFESTS_DIR_NAME|.
+    """
+    # TODO(vapier): Move this out of this class.
+    self.globalConfig = GitConfig.ForUser()
+
    self.repodir = os.path.abspath(repodir)
    self.topdir = os.path.dirname(self.repodir)
-    self.manifestFile = os.path.join(self.repodir, MANIFEST_FILE_NAME)
-    self.globalConfig = GitConfig.ForUser()
-    self.localManifestWarning = False
-    self.isGitcClient = False
+    self.manifestFile = manifest_file
+    self.local_manifests = local_manifests
    self._load_local_manifests = True

    self.repoProject = MetaProject(self, 'repo',
@ -281,18 +281,21 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
    if r.revision is not None:
      e.setAttribute('revision', r.revision)

-  def _ParseGroups(self, groups):
-    return [x for x in re.split(r'[,\s]+', groups) if x]
+  def _ParseList(self, field):
+    """Parse fields that contain flattened lists.

-  def Save(self, fd, peg_rev=False, peg_rev_upstream=True, groups=None):
-    """Write the current manifest out to the given file descriptor.
+    These are whitespace & comma separated.  Empty elements will be discarded.
    """
+    return [x for x in re.split(r'[,\s]+', field) if x]
+
+  def ToXml(self, peg_rev=False, peg_rev_upstream=True, peg_rev_dest_branch=True, groups=None):
+    """Return the current manifest XML."""
    mp = self.manifestProject

    if groups is None:
      groups = mp.config.GetString('manifest.groups')
    if groups:
-      groups = self._ParseGroups(groups)
+      groups = self._ParseList(groups)

    doc = xml.dom.minidom.Document()
    root = doc.createElement('manifest')
@ -389,6 +392,13 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
            # Only save the origin if the origin is not a sha1, and the default
            # isn't our value
            e.setAttribute('upstream', p.revisionExpr)
+
+        if peg_rev_dest_branch:
+          if p.dest_branch:
+            e.setAttribute('dest-branch', p.dest_branch)
+          elif value != p.revisionExpr:
+            e.setAttribute('dest-branch', p.revisionExpr)
+
      else:
        revision = self.remotes[p.remote.orig_name].revision or d.revisionExpr
        if not revision or revision != p.revisionExpr:
@ -453,6 +463,56 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
                     ' '.join(self._repo_hooks_project.enabled_repo_hooks))
      root.appendChild(e)

+    return doc
+
+  def ToDict(self, **kwargs):
+    """Return the current manifest as a dictionary."""
+    # Elements that may only appear once.
+    SINGLE_ELEMENTS = {
+        'notice',
+        'default',
+        'manifest-server',
+        'repo-hooks',
+    }
+    # Elements that may be repeated.
+    MULTI_ELEMENTS = {
+        'remote',
+        'remove-project',
+        'project',
+        'extend-project',
+        'include',
+        # These are children of 'project' nodes.
+        'annotation',
+        'project',
+        'copyfile',
+        'linkfile',
+    }
+
+    doc = self.ToXml(**kwargs)
+    ret = {}
+
+    def append_children(ret, node):
+      for child in node.childNodes:
+        if child.nodeType == xml.dom.Node.ELEMENT_NODE:
+          attrs = child.attributes
+          element = dict((attrs.item(i).localName, attrs.item(i).value)
+                         for i in range(attrs.length))
+          if child.nodeName in SINGLE_ELEMENTS:
+            ret[child.nodeName] = element
+          elif child.nodeName in MULTI_ELEMENTS:
+            ret.setdefault(child.nodeName, []).append(element)
+          else:
+            raise ManifestParseError('Unhandled element "%s"' % (child.nodeName,))
+
+          append_children(element, child)
+
+    append_children(ret, doc.firstChild)
+
+    return ret
+
+  def Save(self, fd, **kwargs):
+    """Write the current manifest out to the given file descriptor."""
+    doc = self.ToXml(**kwargs)
    doc.writexml(fd, '', '  ', '\n', 'UTF-8')

  def _output_manifest_project_extras(self, p, e):
@ -494,6 +554,14 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
    self._Load()
    return self._manifest_server

+  @property
+  def CloneBundle(self):
+    clone_bundle = self.manifestProject.config.GetBoolean('repo.clonebundle')
+    if clone_bundle is None:
+      return False if self.manifestProject.config.GetBoolean('repo.partialclone') else True
+    else:
+      return clone_bundle
+
  @property
  def CloneFilter(self):
    if self.manifestProject.config.GetBoolean('repo.partialclone'):
@ -539,23 +607,11 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
      nodes.append(self._ParseManifestXml(self.manifestFile,
                                          self.manifestProject.worktree))

-      if self._load_local_manifests:
-        local = os.path.join(self.repodir, LOCAL_MANIFEST_NAME)
-        if os.path.exists(local):
-          if not self.localManifestWarning:
-            self.localManifestWarning = True
-            print('warning: %s is deprecated; put local manifests '
-                  'in `%s` instead' % (LOCAL_MANIFEST_NAME,
-                                       os.path.join(self.repodir, LOCAL_MANIFESTS_DIR_NAME)),
-                  file=sys.stderr)
-          nodes.append(self._ParseManifestXml(local, self.repodir))
-
-        local_dir = os.path.abspath(os.path.join(self.repodir,
-                                                 LOCAL_MANIFESTS_DIR_NAME))
+      if self._load_local_manifests and self.local_manifests:
        try:
-          for local_file in sorted(platform_utils.listdir(local_dir)):
+          for local_file in sorted(platform_utils.listdir(self.local_manifests)):
            if local_file.endswith('.xml'):
-              local = os.path.join(local_dir, local_file)
+              local = os.path.join(self.local_manifests, local_file)
              nodes.append(self._ParseManifestXml(local, self.repodir))
        except OSError:
          pass
@ -574,7 +630,7 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md

      self._loaded = True

-  def _ParseManifestXml(self, path, include_root):
+  def _ParseManifestXml(self, path, include_root, parent_groups=''):
    try:
      root = xml.dom.minidom.parse(path)
    except (OSError, xml.parsers.expat.ExpatError) as e:
@ -593,12 +649,17 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
    for node in manifest.childNodes:
      if node.nodeName == 'include':
        name = self._reqatt(node, 'name')
+        include_groups = ''
+        if parent_groups:
+          include_groups = parent_groups
+        if node.hasAttribute('groups'):
+          include_groups = node.getAttribute('groups') + ',' + include_groups
        fp = os.path.join(include_root, name)
        if not os.path.isfile(fp):
          raise ManifestParseError("include %s doesn't exist or isn't a file"
                                   % (name,))
        try:
-          nodes.extend(self._ParseManifestXml(fp, include_root))
+          nodes.extend(self._ParseManifestXml(fp, include_root, include_groups))
        # should isolate this to the exact exception, but that's
        # tricky.  actual parsing implementation may vary.
        except (KeyboardInterrupt, RuntimeError, SystemExit):
@ -607,6 +668,11 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
          raise ManifestParseError(
              "failed parsing included manifest %s: %s" % (name, e))
      else:
+        if parent_groups and node.nodeName == 'project':
+          nodeGroups = parent_groups
+          if node.hasAttribute('groups'):
+            nodeGroups = node.getAttribute('groups') + ',' + nodeGroups
+          node.setAttribute('groups', nodeGroups)
        nodes.append(node)
    return nodes

@ -681,7 +747,7 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
        path = node.getAttribute('path')
        groups = node.getAttribute('groups')
        if groups:
-          groups = self._ParseGroups(groups)
+          groups = self._ParseList(groups)
        revision = node.getAttribute('revision')
        remote = node.getAttribute('remote')
        if remote:
@ -694,12 +760,16 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
            p.groups.extend(groups)
          if revision:
            p.revisionExpr = revision
+            if IsId(revision):
+              p.revisionId = revision
+            else:
+              p.revisionId = None
          if remote:
            p.remote = remote.ToRemoteSpec(name)
      if node.nodeName == 'repo-hooks':
        # Get the name of the project and the (space-separated) list of enabled.
        repo_hooks_project = self._reqatt(node, 'in-project')
-        enabled_repo_hooks = self._reqatt(node, 'enabled-list').split()
+        enabled_repo_hooks = self._ParseList(self._reqatt(node, 'enabled-list'))

        # Only one project can be the hooks project
        if self._repo_hooks_project is not None:
@ -912,7 +982,7 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
    groups = ''
    if node.hasAttribute('groups'):
      groups = node.getAttribute('groups')
-    groups = self._ParseGroups(groups)
+    groups = self._ParseList(groups)

    if parent is None:
      relpath, worktree, gitdir, objdir, use_git_worktrees = \
@ -963,6 +1033,10 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
    return project

  def GetProjectPaths(self, name, path):
+    # The manifest entries might have trailing slashes.  Normalize them to avoid
+    # unexpected filesystem behavior since we do string concatenation below.
+    path = path.rstrip('/')
+    name = name.rstrip('/')
    use_git_worktrees = False
    relpath = path
    if self.IsMirror:
@ -995,6 +1069,10 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
    return os.path.relpath(relpath, parent_relpath)

  def GetSubprojectPaths(self, parent, name, path):
+    # The manifest entries might have trailing slashes.  Normalize them to avoid
+    # unexpected filesystem behavior since we do string concatenation below.
+    path = path.rstrip('/')
+    name = name.rstrip('/')
    relpath = self._JoinRelpath(parent.relpath, path)
    gitdir = os.path.join(parent.gitdir, 'subprojects', '%s.git' % path)
    objdir = os.path.join(parent.gitdir, 'subproject-objects', '%s.git' % name)
@ -1181,15 +1259,7 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md


 class GitcManifest(XmlManifest):
-
-  def __init__(self, repodir, gitc_client_name):
-    """Initialize the GitcManifest object."""
-    super(GitcManifest, self).__init__(repodir)
-    self.isGitcClient = True
-    self.gitc_client_name = gitc_client_name
-    self.gitc_client_dir = os.path.join(gitc_utils.get_gitc_manifest_dir(),
-                                        gitc_client_name)
-    self.manifestFile = os.path.join(self.gitc_client_dir, '.manifest')
+  """Parser for GitC (git-in-the-cloud) manifests."""

  def _ParseProject(self, node, parent=None):
    """Override _ParseProject and add support for GITC specific attributes."""
@ -1200,3 +1270,38 @@ class GitcManifest(XmlManifest):
    """Output GITC Specific Project attributes"""
    if p.old_revision:
      e.setAttribute('old-revision', str(p.old_revision))
+
+
+class RepoClient(XmlManifest):
+  """Manages a repo client checkout."""
+
+  def __init__(self, repodir, manifest_file=None):
+    self.isGitcClient = False
+
+    if os.path.exists(os.path.join(repodir, LOCAL_MANIFEST_NAME)):
+      print('error: %s is not supported; put local manifests in `%s` instead' %
+            (LOCAL_MANIFEST_NAME, os.path.join(repodir, LOCAL_MANIFESTS_DIR_NAME)),
+            file=sys.stderr)
+      sys.exit(1)
+
+    if manifest_file is None:
+      manifest_file = os.path.join(repodir, MANIFEST_FILE_NAME)
+    local_manifests = os.path.abspath(os.path.join(repodir, LOCAL_MANIFESTS_DIR_NAME))
+    super(RepoClient, self).__init__(repodir, manifest_file, local_manifests)
+
+    # TODO: Completely separate manifest logic out of the client.
+    self.manifest = self
+
+
+class GitcClient(RepoClient, GitcManifest):
+  """Manages a GitC client checkout."""
+
+  def __init__(self, repodir, gitc_client_name):
+    """Initialize the GitcManifest object."""
+    self.gitc_client_name = gitc_client_name
+    self.gitc_client_dir = os.path.join(gitc_utils.get_gitc_manifest_dir(),
+                                        gitc_client_name)
+
+    super(GitcManifest, self).__init__(
+        repodir, os.path.join(self.gitc_client_dir, '.manifest'))
+    self.isGitcClient = True
--- a/pager.py
+++ b/pager.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 import os
 import select
 import subprocess
--- a/platform_utils.py
+++ b/platform_utils.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2016 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -17,16 +15,10 @@
 import errno
 import os
 import platform
+from queue import Queue
 import select
 import shutil
 import stat
-
-from pyversion import is_python3
-if is_python3():
-  from queue import Queue
-else:
-  from Queue import Queue
-
 from threading import Thread


--- a/platform_utils_win32.py
+++ b/platform_utils_win32.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2016 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -16,18 +14,10 @@

 import errno

-from pyversion import is_python3
 from ctypes import WinDLL, get_last_error, FormatError, WinError, addressof
-from ctypes import c_buffer
+from ctypes import c_buffer, c_ubyte, Structure, Union, byref
 from ctypes.wintypes import BOOL, BOOLEAN, LPCWSTR, DWORD, HANDLE
-from ctypes.wintypes import WCHAR, USHORT, LPVOID, ULONG
-if is_python3():
-  from ctypes import c_ubyte, Structure, Union, byref
-  from ctypes.wintypes import LPDWORD
-else:
-  # For legacy Python2 different imports are needed.
-  from ctypes.wintypes import POINTER, c_ubyte, Structure, Union, byref
-  LPDWORD = POINTER(DWORD)
+from ctypes.wintypes import WCHAR, USHORT, LPVOID, ULONG, LPDWORD

 kernel32 = WinDLL('kernel32', use_last_error=True)

@ -204,26 +194,15 @@ def readlink(path):
        'Error reading symbolic link \"%s\"'.format(path))
  rdb = REPARSE_DATA_BUFFER.from_buffer(target_buffer)
  if rdb.ReparseTag == IO_REPARSE_TAG_SYMLINK:
-    return _preserve_encoding(path, rdb.SymbolicLinkReparseBuffer.PrintName)
+    return rdb.SymbolicLinkReparseBuffer.PrintName
  elif rdb.ReparseTag == IO_REPARSE_TAG_MOUNT_POINT:
-    return _preserve_encoding(path, rdb.MountPointReparseBuffer.PrintName)
+    return rdb.MountPointReparseBuffer.PrintName
  # Unsupported reparse point type
  _raise_winerror(
      ERROR_NOT_SUPPORTED,
      'Error reading symbolic link \"%s\"'.format(path))


-def _preserve_encoding(source, target):
-  """Ensures target is the same string type (i.e. unicode or str) as source."""
-
-  if is_python3():
-    return target
-
-  if isinstance(source, unicode):  # noqa: F821
-    return unicode(target)  # noqa: F821
-  return str(target)
-
-
 def _raise_winerror(code, error_desc):
  win_error_desc = FormatError(code).strip()
  error_desc = "%s: %s".format(error_desc, win_error_desc)
--- a/progress.py
+++ b/progress.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2009 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
--- a/project.py
+++ b/project.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,11 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 import errno
 import filecmp
 import glob
-import json
 import os
 import random
 import re
@ -29,13 +25,13 @@ import sys
 import tarfile
 import tempfile
 import time
-import traceback
+import urllib.parse

 from color import Coloring
 from git_command import GitCommand, git_require
 from git_config import GitConfig, IsId, GetSchemeFromUrl, GetUrlCookieFile, \
    ID_RE
-from error import GitError, HookError, UploadError, DownloadError
+from error import GitError, UploadError, DownloadError
 from error import ManifestInvalidRevisionError, ManifestInvalidPathError
 from error import NoManifestException
 import platform_utils
@ -44,16 +40,6 @@ from repo_trace import IsTrace, Trace

 from git_refs import GitRefs, HEAD, R_HEADS, R_TAGS, R_PUB, R_M, R_WORKTREE_M

-from pyversion import is_python3
-if is_python3():
-  import urllib.parse
-else:
-  import imp
-  import urlparse
-  urllib = imp.new_module('urllib')
-  urllib.parse = urlparse
-  input = raw_input  # noqa: F821
-

 # Maximum sleep time allowed during retries.
 MAXIMUM_RETRY_SLEEP_SEC = 3600.0
@ -64,7 +50,8 @@ RETRY_JITTER_PERCENT = 0.1
 def _lwrite(path, content):
  lock = '%s.lock' % path

-  with open(lock, 'w') as fd:
+  # Maintain Unix line endings on all OS's to match git behavior.
+  with open(lock, 'w', newline='\n') as fd:
    fd.write(content)

  try:
@ -405,8 +392,8 @@ class _LinkFile(object):
    else:
      src = _SafeExpandPath(self.git_worktree, self.src)

-    if os.path.exists(src):
-      # Entity exists so just a simple one to one link operation.
+    if not glob.has_magic(src):
+      # Entity does not contain a wild card so just a simple one to one link operation.
      dest = _SafeExpandPath(self.topdir, self.dest, skipfinal=True)
      # dest & src are absolute paths at this point.  Make sure the target of
      # the symlink is relative in the context of the repo client checkout.
@ -414,7 +401,7 @@ class _LinkFile(object):
      self.__linkIt(relpath, dest)
    else:
      dest = _SafeExpandPath(self.topdir, self.dest)
-      # Entity doesn't exist assume there is a wild card
+      # Entity contains a wild card.
      if os.path.exists(dest) and not platform_utils.isdir(dest):
        _error('Link error: src with wildcard, %s must be a directory', dest)
      else:
@ -451,406 +438,6 @@ class RemoteSpec(object):
    self.orig_name = orig_name
    self.fetchUrl = fetchUrl

-
-class RepoHook(object):
-
-  """A RepoHook contains information about a script to run as a hook.
-
-  Hooks are used to run a python script before running an upload (for instance,
-  to run presubmit checks).  Eventually, we may have hooks for other actions.
-
-  This shouldn't be confused with files in the 'repo/hooks' directory.  Those
-  files are copied into each '.git/hooks' folder for each project.  Repo-level
-  hooks are associated instead with repo actions.
-
-  Hooks are always python.  When a hook is run, we will load the hook into the
-  interpreter and execute its main() function.
-  """
-
-  def __init__(self,
-               hook_type,
-               hooks_project,
-               topdir,
-               manifest_url,
-               abort_if_user_denies=False):
-    """RepoHook constructor.
-
-    Params:
-      hook_type: A string representing the type of hook.  This is also used
-          to figure out the name of the file containing the hook.  For
-          example: 'pre-upload'.
-      hooks_project: The project containing the repo hooks.  If you have a
-          manifest, this is manifest.repo_hooks_project.  OK if this is None,
-          which will make the hook a no-op.
-      topdir: Repo's top directory (the one containing the .repo directory).
-          Scripts will run with CWD as this directory.  If you have a manifest,
-          this is manifest.topdir
-      manifest_url: The URL to the manifest git repo.
-      abort_if_user_denies: If True, we'll throw a HookError() if the user
-          doesn't allow us to run the hook.
-    """
-    self._hook_type = hook_type
-    self._hooks_project = hooks_project
-    self._manifest_url = manifest_url
-    self._topdir = topdir
-    self._abort_if_user_denies = abort_if_user_denies
-
-    # Store the full path to the script for convenience.
-    if self._hooks_project:
-      self._script_fullpath = os.path.join(self._hooks_project.worktree,
-                                           self._hook_type + '.py')
-    else:
-      self._script_fullpath = None
-
-  def _GetHash(self):
-    """Return a hash of the contents of the hooks directory.
-
-    We'll just use git to do this.  This hash has the property that if anything
-    changes in the directory we will return a different has.
-
-    SECURITY CONSIDERATION:
-      This hash only represents the contents of files in the hook directory, not
-      any other files imported or called by hooks.  Changes to imported files
-      can change the script behavior without affecting the hash.
-
-    Returns:
-      A string representing the hash.  This will always be ASCII so that it can
-      be printed to the user easily.
-    """
-    assert self._hooks_project, "Must have hooks to calculate their hash."
-
-    # We will use the work_git object rather than just calling GetRevisionId().
-    # That gives us a hash of the latest checked in version of the files that
-    # the user will actually be executing.  Specifically, GetRevisionId()
-    # doesn't appear to change even if a user checks out a different version
-    # of the hooks repo (via git checkout) nor if a user commits their own revs.
-    #
-    # NOTE: Local (non-committed) changes will not be factored into this hash.
-    # I think this is OK, since we're really only worried about warning the user
-    # about upstream changes.
-    return self._hooks_project.work_git.rev_parse('HEAD')
-
-  def _GetMustVerb(self):
-    """Return 'must' if the hook is required; 'should' if not."""
-    if self._abort_if_user_denies:
-      return 'must'
-    else:
-      return 'should'
-
-  def _CheckForHookApproval(self):
-    """Check to see whether this hook has been approved.
-
-    We'll accept approval of manifest URLs if they're using secure transports.
-    This way the user can say they trust the manifest hoster.  For insecure
-    hosts, we fall back to checking the hash of the hooks repo.
-
-    Note that we ask permission for each individual hook even though we use
-    the hash of all hooks when detecting changes.  We'd like the user to be
-    able to approve / deny each hook individually.  We only use the hash of all
-    hooks because there is no other easy way to detect changes to local imports.
-
-    Returns:
-      True if this hook is approved to run; False otherwise.
-
-    Raises:
-      HookError: Raised if the user doesn't approve and abort_if_user_denies
-          was passed to the consturctor.
-    """
-    if self._ManifestUrlHasSecureScheme():
-      return self._CheckForHookApprovalManifest()
-    else:
-      return self._CheckForHookApprovalHash()
-
-  def _CheckForHookApprovalHelper(self, subkey, new_val, main_prompt,
-                                  changed_prompt):
-    """Check for approval for a particular attribute and hook.
-
-    Args:
-      subkey: The git config key under [repo.hooks.<hook_type>] to store the
-          last approved string.
-      new_val: The new value to compare against the last approved one.
-      main_prompt: Message to display to the user to ask for approval.
-      changed_prompt: Message explaining why we're re-asking for approval.
-
-    Returns:
-      True if this hook is approved to run; False otherwise.
-
-    Raises:
-      HookError: Raised if the user doesn't approve and abort_if_user_denies
-          was passed to the consturctor.
-    """
-    hooks_config = self._hooks_project.config
-    git_approval_key = 'repo.hooks.%s.%s' % (self._hook_type, subkey)
-
-    # Get the last value that the user approved for this hook; may be None.
-    old_val = hooks_config.GetString(git_approval_key)
-
-    if old_val is not None:
-      # User previously approved hook and asked not to be prompted again.
-      if new_val == old_val:
-        # Approval matched.  We're done.
-        return True
-      else:
-        # Give the user a reason why we're prompting, since they last told
-        # us to "never ask again".
-        prompt = 'WARNING: %s\n\n' % (changed_prompt,)
-    else:
-      prompt = ''
-
-    # Prompt the user if we're not on a tty; on a tty we'll assume "no".
-    if sys.stdout.isatty():
-      prompt += main_prompt + ' (yes/always/NO)? '
-      response = input(prompt).lower()
-      print()
-
-      # User is doing a one-time approval.
-      if response in ('y', 'yes'):
-        return True
-      elif response == 'always':
-        hooks_config.SetString(git_approval_key, new_val)
-        return True
-
-    # For anything else, we'll assume no approval.
-    if self._abort_if_user_denies:
-      raise HookError('You must allow the %s hook or use --no-verify.' %
-                      self._hook_type)
-
-    return False
-
-  def _ManifestUrlHasSecureScheme(self):
-    """Check if the URI for the manifest is a secure transport."""
-    secure_schemes = ('file', 'https', 'ssh', 'persistent-https', 'sso', 'rpc')
-    parse_results = urllib.parse.urlparse(self._manifest_url)
-    return parse_results.scheme in secure_schemes
-
-  def _CheckForHookApprovalManifest(self):
-    """Check whether the user has approved this manifest host.
-
-    Returns:
-      True if this hook is approved to run; False otherwise.
-    """
-    return self._CheckForHookApprovalHelper(
-        'approvedmanifest',
-        self._manifest_url,
-        'Run hook scripts from %s' % (self._manifest_url,),
-        'Manifest URL has changed since %s was allowed.' % (self._hook_type,))
-
-  def _CheckForHookApprovalHash(self):
-    """Check whether the user has approved the hooks repo.
-
-    Returns:
-      True if this hook is approved to run; False otherwise.
-    """
-    prompt = ('Repo %s run the script:\n'
-              '  %s\n'
-              '\n'
-              'Do you want to allow this script to run')
-    return self._CheckForHookApprovalHelper(
-        'approvedhash',
-        self._GetHash(),
-        prompt % (self._GetMustVerb(), self._script_fullpath),
-        'Scripts have changed since %s was allowed.' % (self._hook_type,))
-
-  @staticmethod
-  def _ExtractInterpFromShebang(data):
-    """Extract the interpreter used in the shebang.
-
-    Try to locate the interpreter the script is using (ignoring `env`).
-
-    Args:
-      data: The file content of the script.
-
-    Returns:
-      The basename of the main script interpreter, or None if a shebang is not
-      used or could not be parsed out.
-    """
-    firstline = data.splitlines()[:1]
-    if not firstline:
-      return None
-
-    # The format here can be tricky.
-    shebang = firstline[0].strip()
-    m = re.match(r'^#!\s*([^\s]+)(?:\s+([^\s]+))?', shebang)
-    if not m:
-      return None
-
-    # If the using `env`, find the target program.
-    interp = m.group(1)
-    if os.path.basename(interp) == 'env':
-      interp = m.group(2)
-
-    return interp
-
-  def _ExecuteHookViaReexec(self, interp, context, **kwargs):
-    """Execute the hook script through |interp|.
-
-    Note: Support for this feature should be dropped ~Jun 2021.
-
-    Args:
-      interp: The Python program to run.
-      context: Basic Python context to execute the hook inside.
-      kwargs: Arbitrary arguments to pass to the hook script.
-
-    Raises:
-      HookError: When the hooks failed for any reason.
-    """
-    # This logic needs to be kept in sync with _ExecuteHookViaImport below.
-    script = """
-import json, os, sys
-path = '''%(path)s'''
-kwargs = json.loads('''%(kwargs)s''')
-context = json.loads('''%(context)s''')
-sys.path.insert(0, os.path.dirname(path))
-data = open(path).read()
-exec(compile(data, path, 'exec'), context)
-context['main'](**kwargs)
-""" % {
-        'path': self._script_fullpath,
-        'kwargs': json.dumps(kwargs),
-        'context': json.dumps(context),
-    }
-
-    # We pass the script via stdin to avoid OS argv limits.  It also makes
-    # unhandled exception tracebacks less verbose/confusing for users.
-    cmd = [interp, '-c', 'import sys; exec(sys.stdin.read())']
-    proc = subprocess.Popen(cmd, stdin=subprocess.PIPE)
-    proc.communicate(input=script.encode('utf-8'))
-    if proc.returncode:
-      raise HookError('Failed to run %s hook.' % (self._hook_type,))
-
-  def _ExecuteHookViaImport(self, data, context, **kwargs):
-    """Execute the hook code in |data| directly.
-
-    Args:
-      data: The code of the hook to execute.
-      context: Basic Python context to execute the hook inside.
-      kwargs: Arbitrary arguments to pass to the hook script.
-
-    Raises:
-      HookError: When the hooks failed for any reason.
-    """
-    # Exec, storing global context in the context dict.  We catch exceptions
-    # and convert to a HookError w/ just the failing traceback.
-    try:
-      exec(compile(data, self._script_fullpath, 'exec'), context)
-    except Exception:
-      raise HookError('%s\nFailed to import %s hook; see traceback above.' %
-                      (traceback.format_exc(), self._hook_type))
-
-    # Running the script should have defined a main() function.
-    if 'main' not in context:
-      raise HookError('Missing main() in: "%s"' % self._script_fullpath)
-
-    # Call the main function in the hook.  If the hook should cause the
-    # build to fail, it will raise an Exception.  We'll catch that convert
-    # to a HookError w/ just the failing traceback.
-    try:
-      context['main'](**kwargs)
-    except Exception:
-      raise HookError('%s\nFailed to run main() for %s hook; see traceback '
-                      'above.' % (traceback.format_exc(), self._hook_type))
-
-  def _ExecuteHook(self, **kwargs):
-    """Actually execute the given hook.
-
-    This will run the hook's 'main' function in our python interpreter.
-
-    Args:
-      kwargs: Keyword arguments to pass to the hook.  These are often specific
-          to the hook type.  For instance, pre-upload hooks will contain
-          a project_list.
-    """
-    # Keep sys.path and CWD stashed away so that we can always restore them
-    # upon function exit.
-    orig_path = os.getcwd()
-    orig_syspath = sys.path
-
-    try:
-      # Always run hooks with CWD as topdir.
-      os.chdir(self._topdir)
-
-      # Put the hook dir as the first item of sys.path so hooks can do
-      # relative imports.  We want to replace the repo dir as [0] so
-      # hooks can't import repo files.
-      sys.path = [os.path.dirname(self._script_fullpath)] + sys.path[1:]
-
-      # Initial global context for the hook to run within.
-      context = {'__file__': self._script_fullpath}
-
-      # Add 'hook_should_take_kwargs' to the arguments to be passed to main.
-      # We don't actually want hooks to define their main with this argument--
-      # it's there to remind them that their hook should always take **kwargs.
-      # For instance, a pre-upload hook should be defined like:
-      #   def main(project_list, **kwargs):
-      #
-      # This allows us to later expand the API without breaking old hooks.
-      kwargs = kwargs.copy()
-      kwargs['hook_should_take_kwargs'] = True
-
-      # See what version of python the hook has been written against.
-      data = open(self._script_fullpath).read()
-      interp = self._ExtractInterpFromShebang(data)
-      reexec = False
-      if interp:
-        prog = os.path.basename(interp)
-        if prog.startswith('python2') and sys.version_info.major != 2:
-          reexec = True
-        elif prog.startswith('python3') and sys.version_info.major == 2:
-          reexec = True
-
-      # Attempt to execute the hooks through the requested version of Python.
-      if reexec:
-        try:
-          self._ExecuteHookViaReexec(interp, context, **kwargs)
-        except OSError as e:
-          if e.errno == errno.ENOENT:
-            # We couldn't find the interpreter, so fallback to importing.
-            reexec = False
-          else:
-            raise
-
-      # Run the hook by importing directly.
-      if not reexec:
-        self._ExecuteHookViaImport(data, context, **kwargs)
-    finally:
-      # Restore sys.path and CWD.
-      sys.path = orig_syspath
-      os.chdir(orig_path)
-
-  def Run(self, user_allows_all_hooks, **kwargs):
-    """Run the hook.
-
-    If the hook doesn't exist (because there is no hooks project or because
-    this particular hook is not enabled), this is a no-op.
-
-    Args:
-      user_allows_all_hooks: If True, we will never prompt about running the
-          hook--we'll just assume it's OK to run it.
-      kwargs: Keyword arguments to pass to the hook.  These are often specific
-          to the hook type.  For instance, pre-upload hooks will contain
-          a project_list.
-
-    Raises:
-      HookError: If there was a problem finding the hook or the user declined
-          to run a required hook (from _CheckForHookApproval).
-    """
-    # No-op if there is no hooks project or if hook is disabled.
-    if ((not self._hooks_project) or (self._hook_type not in
-                                      self._hooks_project.enabled_repo_hooks)):
-      return
-
-    # Bail with a nice error if we can't find the hook.
-    if not os.path.isfile(self._script_fullpath):
-      raise HookError('Couldn\'t find repo hook: "%s"' % self._script_fullpath)
-
-    # Make sure the user is OK with running the hook.
-    if (not user_allows_all_hooks) and (not self._CheckForHookApproval()):
-      return
-
-    # Run the hook with the same version of python we're using.
-    self._ExecuteHook(**kwargs)
-
-
 class Project(object):
  # These objects can be shared between several working trees.
  shareable_files = ['description', 'info']
@ -912,7 +499,7 @@ class Project(object):
                     with exponential backoff and jitter.
      old_revision: saved git commit id for open GITC projects.
    """
-    self.manifest = manifest
+    self.client = self.manifest = manifest
    self.name = name
    self.remote = remote
    self.gitdir = gitdir.replace('\\', '/')
@ -953,7 +540,7 @@ class Project(object):
    self.linkfiles = []
    self.annotations = []
    self.config = GitConfig.ForRepository(gitdir=self.gitdir,
-                                          defaults=self.manifest.globalConfig)
+                                          defaults=self.client.globalConfig)

    if self.worktree:
      self.work_git = self._GitGetByExec(self, bare=False, gitdir=gitdir)
@ -1428,10 +1015,11 @@ class Project(object):
    if GitCommand(self, cmd, bare=True).Wait() != 0:
      raise UploadError('Upload failed')

-    msg = "posted to %s for %s" % (branch.remote.review, dest_branch)
-    self.bare_git.UpdateRef(R_PUB + branch.name,
-                            R_HEADS + branch.name,
-                            message=msg)
+    if not dryrun:
+      msg = "posted to %s for %s" % (branch.remote.review, dest_branch)
+      self.bare_git.UpdateRef(R_PUB + branch.name,
+                              R_HEADS + branch.name,
+                              message=msg)

 # Sync ##
  def _ExtractArchive(self, tarpath, path=None):
@ -1570,7 +1158,7 @@ class Project(object):
    self._InitHooks()

  def _CopyAndLinkFiles(self):
-    if self.manifest.isGitcClient:
+    if self.client.isGitcClient:
      return
    for copyfile in self.copyfiles:
      copyfile._Copy()
@ -2311,6 +1899,27 @@ class Project(object):
    # Enable the extension!
    self.config.SetString('extensions.%s' % (key,), value)

+  def ResolveRemoteHead(self, name=None):
+    """Find out what the default branch (HEAD) points to.
+
+    Normally this points to refs/heads/master, but projects are moving to main.
+    Support whatever the server uses rather than hardcoding "master" ourselves.
+    """
+    if name is None:
+      name = self.remote.name
+
+    # The output will look like (NB: tabs are separators):
+    # ref: refs/heads/master	HEAD
+    # 5f6803b100bb3cd0f534e96e88c91373e8ed1c44	HEAD
+    output = self.bare_git.ls_remote('-q', '--symref', '--exit-code', name, 'HEAD')
+
+    for line in output.splitlines():
+      lhs, rhs = line.split('\t', 1)
+      if rhs == 'HEAD' and lhs.startswith('ref:'):
+        return lhs[4:].strip()
+
+    return None
+
  def _CheckForImmutableRevision(self):
    try:
      # if revision (sha or tag) is not present then following function
@ -2793,7 +2402,7 @@ class Project(object):

          # Enable per-worktree config file support if possible.  This is more a
          # nice-to-have feature for users rather than a hard requirement.
-          if git_require((2, 19, 0)):
+          if git_require((2, 20, 0)):
            self.EnableRepositoryExtension('worktreeConfig')

      # If we have a separate directory to hold refs, initialize it as well.
@ -2937,6 +2546,8 @@ class Project(object):

        base = R_WORKTREE_M
        active_git = self.work_git
+
+        self._InitAnyMRef(HEAD, self.bare_git, detach=True)
      else:
        base = R_M
        active_git = self.bare_git
@ -2946,7 +2557,7 @@ class Project(object):
  def _InitMirrorHead(self):
    self._InitAnyMRef(HEAD, self.bare_git)

-  def _InitAnyMRef(self, ref, active_git):
+  def _InitAnyMRef(self, ref, active_git, detach=False):
    cur = self.bare_ref.symref(ref)

    if self.revisionId:
@ -2959,7 +2570,10 @@ class Project(object):
      dst = remote.ToLocal(self.revisionExpr)
      if cur != dst:
        msg = 'manifest set to %s' % self.revisionExpr
-        active_git.symbolic_ref('-m', msg, ref, dst)
+        if detach:
+          active_git.UpdateRef(ref, dst, message=msg, detach=True)
+        else:
+          active_git.symbolic_ref('-m', msg, ref, dst)

  def _CheckDirReference(self, srcdir, destdir, share_refs):
    # Git worktrees don't use symlinks to share at all.
@ -3082,12 +2696,14 @@ class Project(object):
    # Some platforms (e.g. Windows) won't let us update dotgit in situ because
    # of file permissions.  Delete it and recreate it from scratch to avoid.
    platform_utils.remove(dotgit)
-    # Use relative path from checkout->worktree.
-    with open(dotgit, 'w') as fp:
+    # Use relative path from checkout->worktree & maintain Unix line endings
+    # on all OS's to match git behavior.
+    with open(dotgit, 'w', newline='\n') as fp:
      print('gitdir:', os.path.relpath(git_worktree_path, self.worktree),
            file=fp)
-    # Use relative path from worktree->checkout.
-    with open(os.path.join(git_worktree_path, 'gitdir'), 'w') as fp:
+    # Use relative path from worktree->checkout & maintain Unix line endings
+    # on all OS's to match git behavior.
+    with open(os.path.join(git_worktree_path, 'gitdir'), 'w', newline='\n') as fp:
      print(os.path.relpath(dotgit, git_worktree_path), file=fp)

    self._InitMRef()
@ -3208,6 +2824,13 @@ class Project(object):
      self._bare = bare
      self._gitdir = gitdir

+    # __getstate__ and __setstate__ are required for pickling because __getattr__ exists.
+    def __getstate__(self):
+      return (self._project, self._bare, self._gitdir)
+
+    def __setstate__(self, state):
+      self._project, self._bare, self._gitdir = state
+
    def LsOthers(self):
      p = GitCommand(self._project,
                     ['ls-files',
--- a/pyversion.py
+++ b/pyversion.py
@ -1,21 +0,0 @@
-# -*- coding:utf-8 -*-
-#
-# Copyright (C) 2013 The Android Open Source Project
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-import sys
-
-
-def is_python3():
-  return sys.version_info[0] == 3
--- a/release/sign-tag.py
+++ b/release/sign-tag.py
@ -18,11 +18,7 @@
 This is intended to be run only by the official Repo release managers, but it
 could be run by people maintaining their own fork of the project.

-NB: Avoid new releases on off-hours.  If something goes wrong, staff/oncall need
-to be active in order to respond quickly & effectively.  Recommend sticking to:
-* Mon - Thu, 9:00 - 14:00 PT (i.e. MTV time)
-* Avoid US holidays (and large international ones if possible)
-* Follow the normal Google production freeze schedule
+NB: Check docs/release-process.md for production freeze information.
 """

 import argparse
--- a/65
+++ b/65
@ -32,6 +32,13 @@ import subprocess
 import sys


+# These should never be newer than the main.py version since this needs to be a
+# bit more flexible with older systems.  See that file for more details on the
+# versions we select.
+MIN_PYTHON_VERSION_SOFT = (3, 6)
+MIN_PYTHON_VERSION_HARD = (3, 5)
+
+
 # Keep basic logic in sync with repo_trace.py.
 class Trace(object):
  """Trace helper logic."""
@ -70,8 +77,6 @@ def check_python_version():
  def reexec(prog):
    exec_command([prog] + sys.argv)

-  MIN_PYTHON_VERSION = (3, 6)
-
  ver = sys.version_info
  major = ver.major
  minor = ver.minor
@ -80,19 +85,26 @@ def check_python_version():
  if (major, minor) < (2, 7):
    print('repo: error: Your Python version is too old. '
          'Please use Python {}.{} or newer instead.'.format(
-              *MIN_PYTHON_VERSION), file=sys.stderr)
+              *MIN_PYTHON_VERSION_SOFT), file=sys.stderr)
    sys.exit(1)

  # Try to re-exec the version specific Python 3 if needed.
-  if (major, minor) < MIN_PYTHON_VERSION:
+  if (major, minor) < MIN_PYTHON_VERSION_SOFT:
    # Python makes releases ~once a year, so try our min version +10 to help
    # bridge the gap.  This is the fallback anyways so perf isn't critical.
-    min_major, min_minor = MIN_PYTHON_VERSION
+    min_major, min_minor = MIN_PYTHON_VERSION_SOFT
    for inc in range(0, 10):
      reexec('python{}.{}'.format(min_major, min_minor + inc))

-    # Try the generic Python 3 wrapper, but only if it's new enough.  We don't
-    # want to go from (still supported) Python 2.7 to (unsupported) Python 3.5.
+    # Fallback to older versions if possible.
+    for inc in range(MIN_PYTHON_VERSION_SOFT[1] - MIN_PYTHON_VERSION_HARD[1], 0, -1):
+      # Don't downgrade, and don't reexec ourselves (which would infinite loop).
+      if (min_major, min_minor - inc) <= (major, minor):
+        break
+      reexec('python{}.{}'.format(min_major, min_minor - inc))
+
+    # Try the generic Python 3 wrapper, but only if it's new enough.  If it
+    # isn't, we want to just give up below and make the user resolve things.
    try:
      proc = subprocess.Popen(
          ['python3', '-c', 'import sys; '
@ -103,18 +115,20 @@ def check_python_version():
    except (OSError, subprocess.CalledProcessError):
      python3_ver = None

-    # The python3 version looks like it's new enough, so give it a try.
-    if python3_ver and python3_ver >= MIN_PYTHON_VERSION:
+    # If the python3 version looks like it's new enough, give it a try.
+    if (python3_ver and python3_ver >= MIN_PYTHON_VERSION_HARD
+        and python3_ver != (major, minor)):
      reexec('python3')

    # We're still here, so diagnose things for the user.
    if major < 3:
-      print('repo: warning: Python 2 is no longer supported; '
-            'Please upgrade to Python {}.{}+.'.format(*MIN_PYTHON_VERSION),
+      print('repo: error: Python 2 is no longer supported; '
+            'Please upgrade to Python {}.{}+.'.format(*MIN_PYTHON_VERSION_HARD),
            file=sys.stderr)
-    else:
+      sys.exit(1)
+    elif (major, minor) < MIN_PYTHON_VERSION_HARD:
      print('repo: error: Python 3 version is too old; '
-            'Please use Python {}.{} or newer.'.format(*MIN_PYTHON_VERSION),
+            'Please use Python {}.{} or newer.'.format(*MIN_PYTHON_VERSION_HARD),
            file=sys.stderr)
      sys.exit(1)

@ -133,7 +147,7 @@ if not REPO_REV:
  REPO_REV = 'stable'

 # increment this whenever we make important changes to this script
-VERSION = (2, 5)
+VERSION = (2, 11)

 # increment this if the MAINTAINER_KEYS block is modified
 KEYRING_VERSION = (2, 3)
@ -317,9 +331,11 @@ def GetParser(gitc_init=False):
                   help='restrict manifest projects to ones with a specified '
                        'platform group [auto|all|none|linux|darwin|...]',
                   metavar='PLATFORM')
+  group.add_option('--clone-bundle', action='store_true',
+                   help='enable use of /clone.bundle on HTTP/HTTPS (default if not --partial-clone)')
  group.add_option('--no-clone-bundle',
-                   dest='clone_bundle', default=True, action='store_false',
-                   help='disable use of /clone.bundle on HTTP/HTTPS')
+                   dest='clone_bundle', action='store_false',
+                   help='disable use of /clone.bundle on HTTP/HTTPS (default if --partial-clone)')
  group.add_option('--no-tags',
                   dest='tags', default=True, action='store_false',
                   help="don't fetch tags in the manifest")
@ -437,9 +453,11 @@ def get_gitc_manifest_dir():
 def gitc_parse_clientdir(gitc_fs_path):
  """Parse a path in the GITC FS and return its client name.

-  @param gitc_fs_path: A subdirectory path within the GITC_FS_ROOT_DIR.
+  Args:
+    gitc_fs_path: A subdirectory path within the GITC_FS_ROOT_DIR.

-  @returns: The GITC client name
+  Returns:
+    The GITC client name.
  """
  if gitc_fs_path == GITC_FS_ROOT_DIR:
    return None
@ -502,6 +520,9 @@ def _Init(args, gitc_init=False):
  opt.quiet = opt.output_mode is False
  opt.verbose = opt.output_mode is True

+  if opt.clone_bundle is None:
+    opt.clone_bundle = False if opt.partial_clone else True
+
  url = opt.repo_url or REPO_URL
  rev = opt.repo_rev or REPO_REV

@ -961,9 +982,7 @@ def _FindRepo():
  repo = None

  olddir = None
-  while curdir != '/' \
-          and curdir != olddir \
-          and not repo:
+  while curdir != olddir and not repo:
    repo = os.path.join(curdir, repodir, REPO_MAIN)
    if not os.path.isfile(repo):
      repo = None
@ -1169,6 +1188,10 @@ def main(orig_args):
  if my_main:
    repo_main = my_main

+  if not repo_main:
+    print("fatal: unable to find repo entry point", file=sys.stderr)
+    sys.exit(1)
+
  ver_str = '.'.join(map(str, VERSION))
  me = [sys.executable, repo_main,
        '--repo-dir=%s' % rel_repo_dir,
--- a/repo_trace.py
+++ b/repo_trace.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -19,7 +17,6 @@
 Activated via `repo --trace ...` or `REPO_TRACE=1 repo ...`.
 """

-from __future__ import print_function
 import sys
 import os

--- a/36
+++ b/36
@ -1,5 +1,4 @@
-#!/usr/bin/env python
-# -*- coding:utf-8 -*-
+#!/usr/bin/env python3
 # Copyright 2019 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -16,26 +15,28 @@

 """Wrapper to run pytest with the right settings."""

-from __future__ import print_function
-
 import errno
 import os
+import shutil
 import subprocess
 import sys


-def run_pytest(cmd, argv):
-  """Run the unittests via |cmd|."""
-  try:
-    return subprocess.call([cmd] + argv)
-  except OSError as e:
-    if e.errno == errno.ENOENT:
-      print('%s: unable to run `%s`: %s' % (__file__, cmd, e), file=sys.stderr)
-      print('%s: Try installing pytest: sudo apt-get install python-pytest' %
-            (__file__,), file=sys.stderr)
-      return 127
-    else:
-      raise
+def find_pytest():
+  """Try to locate a good version of pytest."""
+  # Use the Python 3 version if available.
+  ret = shutil.which('pytest-3')
+  if ret:
+    return ret
+
+  # Hopefully this is a Python 3 version.
+  ret = shutil.which('pytest')
+  if ret:
+    return ret
+
+  print(f'{__file__}: unable to find pytest.', file=sys.stderr)
+  print(f'{__file__}: Try installing: sudo apt-get install python-pytest',
+        file=sys.stderr)


 def main(argv):
@ -48,7 +49,8 @@ def main(argv):
    pythonpath += os.pathsep + oldpythonpath
  os.environ['PYTHONPATH'] = pythonpath

-  return run_pytest('pytest', argv)
+  pytest = find_pytest()
+  return subprocess.run([pytest] + argv, check=True)


 if __name__ == '__main__':
--- a/setup.py
+++ b/setup.py
@ -1,5 +1,4 @@
-#!/usr/bin/env python
-# -*- coding:utf-8 -*-
+#!/usr/bin/env python3
 # Copyright 2019 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the 'License");
@ -16,8 +15,6 @@

 """Python packaging for repo."""

-from __future__ import print_function
-
 import os
 import setuptools

@ -55,9 +52,10 @@ setuptools.setup(
        'Operating System :: MacOS :: MacOS X',
        'Operating System :: Microsoft :: Windows :: Windows 10',
        'Operating System :: POSIX :: Linux',
+        'Programming Language :: Python :: 3',
+        'Programming Language :: Python :: 3 :: Only',
        'Topic :: Software Development :: Version Control :: Git',
    ],
-    # We support Python 2.7 and Python 3.6+.
-    python_requires='>=2.7, ' + ', '.join('!=3.%i.*' % x for x in range(0, 6)),
+    python_requires='>=3.6',
    packages=['subcmds'],
 )
--- a/subcmds/init.py
+++ b/subcmds/init.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
--- a/subcmds/abandon.py
+++ b/subcmds/abandon.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,8 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
-
 from collections import defaultdict
 import sys

--- a/subcmds/branches.py
+++ b/subcmds/branches.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2009 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,11 +12,20 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
+import itertools
+import multiprocessing
 import sys
 from color import Coloring
 from command import Command

+# Number of projects to submit to a single worker process at a time.
+# This number represents a tradeoff between the overhead of IPC and finer
+# grained opportunity for parallelism. This particular value was chosen by
+# iterating through powers of two until the overall performance no longer
+# improved. The performance of this batch size is not a function of the
+# number of cores on the system.
+WORKER_BATCH_SIZE = 32
+

 class BranchColoring(Coloring):
  def __init__(self, config):
@ -97,20 +104,32 @@ is shown, then the branch appears in all projects.

 """

+  def _Options(self, p):
+    """Add flags to CLI parser for this subcommand."""
+    default_jobs = min(multiprocessing.cpu_count(), 8)
+    p.add_option(
+        '-j',
+        '--jobs',
+        type=int,
+        default=default_jobs,
+        help='Number of worker processes to spawn '
+        '(default: %s)' % default_jobs)
+
  def Execute(self, opt, args):
    projects = self.GetProjects(args)
    out = BranchColoring(self.manifest.manifestProject.config)
    all_branches = {}
    project_cnt = len(projects)
+    with multiprocessing.Pool(processes=opt.jobs) as pool:
+      project_branches = pool.imap_unordered(
+          expand_project_to_branches, projects, chunksize=WORKER_BATCH_SIZE)

-    for project in projects:
-      for name, b in project.GetBranches().items():
-        b.project = project
+      for name, b in itertools.chain.from_iterable(project_branches):
        if name not in all_branches:
          all_branches[name] = BranchInfo(name)
        all_branches[name].add(b)

-    names = list(sorted(all_branches))
+    names = sorted(all_branches)

    if not names:
      print('   (no branches)', file=sys.stderr)
@ -180,3 +199,19 @@ is shown, then the branch appears in all projects.
      else:
        out.write(' in all projects')
      out.nl()
+
+
+def expand_project_to_branches(project):
+  """Expands a project into a list of branch names & associated information.
+
+  Args:
+    project: project.Project
+
+  Returns:
+    List[Tuple[str, git_config.Branch]]
+  """
+  branches = []
+  for name, b in project.GetBranches().items():
+    b.project = project
+    branches.append((name, b))
+  return branches
--- a/subcmds/checkout.py
+++ b/subcmds/checkout.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2009 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 import sys
 from command import Command
 from progress import Progress
--- a/subcmds/cherry_pick.py
+++ b/subcmds/cherry_pick.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2010 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 import re
 import sys
 from command import Command
--- a/subcmds/diff.py
+++ b/subcmds/diff.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
--- a/subcmds/diffmanifests.py
+++ b/subcmds/diffmanifests.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2014 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -16,7 +14,7 @@

 from color import Coloring
 from command import PagedCommand
-from manifest_xml import XmlManifest
+from manifest_xml import RepoClient


 class _Coloring(Coloring):
@ -183,7 +181,7 @@ synced and their revisions won't be found.
      self.OptionParser.error('missing manifests to diff')

  def Execute(self, opt, args):
-    self.out = _Coloring(self.manifest.globalConfig)
+    self.out = _Coloring(self.client.globalConfig)
    self.printText = self.out.nofmt_printer('text')
    if opt.color:
      self.printProject = self.out.nofmt_printer('project', attr='bold')
@ -193,12 +191,12 @@ synced and their revisions won't be found.
    else:
      self.printProject = self.printAdded = self.printRemoved = self.printRevision = self.printText

-    manifest1 = XmlManifest(self.manifest.repodir)
+    manifest1 = RepoClient(self.manifest.repodir)
    manifest1.Override(args[0], load_local_manifests=False)
    if len(args) == 1:
      manifest2 = self.manifest
    else:
-      manifest2 = XmlManifest(self.manifest.repodir)
+      manifest2 = RepoClient(self.manifest.repodir)
      manifest2.Override(args[1], load_local_manifests=False)

    diff = manifest1.projectsDiff(manifest2)
--- a/subcmds/download.py
+++ b/subcmds/download.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 import re
 import sys

--- a/subcmds/forall.py
+++ b/subcmds/forall.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 import errno
 import multiprocessing
 import re
@ -179,6 +176,8 @@ without iterating through the remaining projects.
        'annotations': dict((a.name, a.value) for a in project.annotations),
        'gitdir': project.gitdir,
        'worktree': project.worktree,
+        'upstream': project.upstream,
+        'dest_branch': project.dest_branch,
    }

  def ValidateOptions(self, opt, args):
@ -317,6 +316,8 @@ def DoWork(project, mirror, opt, cmd, shell, cnt, config):
  setenv('REPO_REMOTE', project['remote_name'])
  setenv('REPO_LREV', project['lrev'])
  setenv('REPO_RREV', project['rrev'])
+  setenv('REPO_UPSTREAM', project['upstream'])
+  setenv('REPO_DEST_BRANCH', project['dest_branch'])
  setenv('REPO_I', str(cnt + 1))
  for name in project['annotations']:
    setenv("REPO__%s" % (name), project['annotations'][name])
--- a/subcmds/gitc_delete.py
+++ b/subcmds/gitc_delete.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2015 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,16 +12,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 import sys

 from command import Command, GitcClientCommand
 import platform_utils

-from pyversion import is_python3
-if not is_python3():
-  input = raw_input  # noqa: F821
-

 class GitcDelete(Command, GitcClientCommand):
  common = True
--- a/subcmds/gitc_init.py
+++ b/subcmds/gitc_init.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2015 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 import os
 import sys

--- a/subcmds/grep.py
+++ b/subcmds/grep.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2009 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,8 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
-
 import sys

 from color import Coloring
--- a/subcmds/help.py
+++ b/subcmds/help.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 import re
 import sys
 from formatter import AbstractFormatter, DumbWriter
@ -65,7 +62,7 @@ Displays detailed usage information about a command.
    def gitc_supported(cmd):
      if not isinstance(cmd, GitcAvailableCommand) and not isinstance(cmd, GitcClientCommand):
        return True
-      if self.manifest.isGitcClient:
+      if self.client.isGitcClient:
        return True
      if isinstance(cmd, GitcClientCommand):
        return False
@ -127,7 +124,7 @@ Displays detailed usage information about a command.
          self.wrap.end_paragraph(1)
        self.wrap.end_paragraph(0)

-    out = _Out(self.manifest.globalConfig)
+    out = _Out(self.client.globalConfig)
    out._PrintSection('Summary', 'helpSummary')
    cmd.OptionParser.print_help()
    out._PrintSection('Description', 'helpDescription')
--- a/subcmds/info.py
+++ b/subcmds/info.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2012 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -16,7 +14,7 @@

 from command import PagedCommand
 from color import Coloring
-from git_refs import R_M
+from git_refs import R_M, R_HEADS


 class _Coloring(Coloring):
@ -44,7 +42,7 @@ class Info(PagedCommand):
                 help="Disable all remote operations")

  def Execute(self, opt, args):
-    self.out = _Coloring(self.manifest.globalConfig)
+    self.out = _Coloring(self.client.globalConfig)
    self.heading = self.out.printer('heading', attr='bold')
    self.headtext = self.out.nofmt_printer('headtext', fg='yellow')
    self.redtext = self.out.printer('redtext', fg='red')
@ -127,7 +125,10 @@ class Info(PagedCommand):
    if not self.opt.local:
      project.Sync_NetworkHalf(quiet=True, current_branch_only=True)

-    logTarget = R_M + self.manifest.manifestProject.config.GetBranch("default").merge
+    branch = self.manifest.manifestProject.config.GetBranch('default').merge
+    if branch.startswith(R_HEADS):
+      branch = branch[len(R_HEADS):]
+    logTarget = R_M + branch

    bareTmp = project.bare_git._bare
    project.bare_git._bare = False
--- a/subcmds/init.py
+++ b/subcmds/init.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,22 +12,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
-
 import optparse
 import os
 import platform
 import re
 import sys
-
-from pyversion import is_python3
-if is_python3():
-  import urllib.parse
-else:
-  import imp
-  import urlparse
-  urllib = imp.new_module('urllib')
-  urllib.parse = urlparse
+import urllib.parse

 from color import Coloring
 from command import InteractiveCommand, MirrorSafeCommand
@ -54,7 +42,8 @@ from the server and is installed in the .repo/ directory in the
 current working directory.

 The optional -b argument can be used to select the manifest branch
-to checkout and use.  If no branch is specified, master is assumed.
+to checkout and use.  If no branch is specified, the remote's default
+branch is used.

 The optional -m argument can be used to specify an alternate manifest
 to be used. If no manifest is specified, the manifest default.xml
@ -155,9 +144,11 @@ to update the working directory files.
                 help='restrict manifest projects to ones with a specified '
                      'platform group [auto|all|none|linux|darwin|...]',
                 metavar='PLATFORM')
+    g.add_option('--clone-bundle', action='store_true',
+                 help='force use of /clone.bundle on HTTP/HTTPS (default if not --partial-clone)')
    g.add_option('--no-clone-bundle',
-                 dest='clone_bundle', default=True, action='store_false',
-                 help='disable use of /clone.bundle on HTTP/HTTPS')
+                 dest='clone_bundle', action='store_false',
+                 help='disable use of /clone.bundle on HTTP/HTTPS (default if --partial-clone)')
    g.add_option('--no-tags',
                 dest='tags', default=True, action='store_false',
                 help="don't fetch tags in the manifest")
@ -213,24 +204,27 @@ to update the working directory files.

      m._InitGitDir(mirror_git=mirrored_manifest_git)

-      if opt.manifest_branch:
-        m.revisionExpr = opt.manifest_branch
-      else:
-        m.revisionExpr = 'refs/heads/master'
-    else:
-      if opt.manifest_branch:
-        m.revisionExpr = opt.manifest_branch
-      else:
-        m.PreSync()
-
    self._ConfigureDepth(opt)

+    # Set the remote URL before the remote branch as we might need it below.
    if opt.manifest_url:
      r = m.GetRemote(m.remote.name)
      r.url = opt.manifest_url
      r.ResetFetch()
      r.Save()

+    if opt.manifest_branch:
+      m.revisionExpr = opt.manifest_branch
+    else:
+      if is_new:
+        default_branch = m.ResolveRemoteHead()
+        if default_branch is None:
+          # If the remote doesn't have HEAD configured, default to master.
+          default_branch = 'refs/heads/master'
+        m.revisionExpr = default_branch
+      else:
+        m.PreSync()
+
    groups = re.split(r'[,\s]+', opt.groups)
    all_platforms = ['linux', 'darwin', 'windows']
    platformize = lambda x: 'platform-' + x
@ -303,6 +297,11 @@ to update the working directory files.
    else:
      opt.clone_filter = None

+    if opt.clone_bundle is None:
+      opt.clone_bundle = False if opt.partial_clone else True
+    else:
+      m.config.SetString('repo.clonebundle', 'true' if opt.clone_bundle else 'false')
+
    if opt.submodules:
      m.config.SetString('repo.submodules', 'true')

@ -354,7 +353,7 @@ to update the working directory files.
    return a

  def _ShouldConfigureUser(self, opt):
-    gc = self.manifest.globalConfig
+    gc = self.client.globalConfig
    mp = self.manifest.manifestProject

    # If we don't have local settings, get from global.
@ -403,7 +402,7 @@ to update the working directory files.
    return False

  def _ConfigureColor(self):
-    gc = self.manifest.globalConfig
+    gc = self.client.globalConfig
    if self._HasColorSet(gc):
      return

@ -481,6 +480,9 @@ to update the working directory files.
    if opt.archive and opt.mirror:
      self.OptionParser.error('--mirror and --archive cannot be used together.')

+    if args:
+      self.OptionParser.error('init takes no arguments')
+
  def Execute(self, opt, args):
    git_require(MIN_GIT_VERSION_HARD, fail=True)
    if not git_require(MIN_GIT_VERSION_SOFT):
@ -507,7 +509,7 @@ to update the working directory files.
          rp.gitdir, opt.repo_rev, repo_verify=opt.repo_verify, quiet=opt.quiet)
      branch = rp.GetBranch('default')
      branch.merge = remote_ref
-      rp.work_git.update_ref('refs/heads/default', rev)
+      rp.work_git.reset('--hard', rev)
      branch.Save()

    if opt.worktree:
--- a/subcmds/list.py
+++ b/subcmds/list.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2011 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,8 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
-
 from command import Command, MirrorSafeCommand


--- a/subcmds/manifest.py
+++ b/subcmds/manifest.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2009 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
+import json
 import os
 import sys

@ -30,10 +28,16 @@ class Manifest(PagedCommand):
  _helpDescription = """

 With the -o option, exports the current manifest for inspection.
-The manifest and (if present) local_manifest.xml are combined
+The manifest and (if present) local_manifests/ are combined
 together to produce a single manifest file.  This file can be stored
 in a Git repository for use during future 'repo init' invocations.

+The -r option can be used to generate a manifest file with project
+revisions set to the current commit hash.  These are known as
+"revision locked manifests", as they don't follow a particular branch.
+In this case, the 'upstream' attribute is set to the ref we were on
+when the manifest was generated.  The 'dest-branch' attribute is set
+to indicate the remote ref to push changes to via 'repo upload'.
 """

  @property
@ -57,6 +61,15 @@ in a Git repository for use during future 'repo init' invocations.
                 help='If in -r mode, do not write the upstream field.  '
                 'Only of use if the branch names for a sha1 manifest are '
                 'sensitive.')
+    p.add_option('--suppress-dest-branch', dest='peg_rev_dest_branch',
+                 default=True, action='store_false',
+                 help='If in -r mode, do not write the dest-branch field.  '
+                 'Only of use if the branch names for a sha1 manifest are '
+                 'sensitive.')
+    p.add_option('--json', default=False, action='store_true',
+                 help='Output manifest in JSON format (experimental).')
+    p.add_option('--pretty', default=False, action='store_true',
+                 help='Format output for humans to read.')
    p.add_option('-o', '--output-file',
                 dest='output_file',
                 default='-',
@ -72,9 +85,26 @@ in a Git repository for use during future 'repo init' invocations.
      fd = sys.stdout
    else:
      fd = open(opt.output_file, 'w')
-    self.manifest.Save(fd,
-                       peg_rev=opt.peg_rev,
-                       peg_rev_upstream=opt.peg_rev_upstream)
+    if opt.json:
+      print('warning: --json is experimental!', file=sys.stderr)
+      doc = self.manifest.ToDict(peg_rev=opt.peg_rev,
+                                 peg_rev_upstream=opt.peg_rev_upstream,
+                                 peg_rev_dest_branch=opt.peg_rev_dest_branch)
+
+      json_settings = {
+          # JSON style guide says Uunicode characters are fully allowed.
+          'ensure_ascii': False,
+          # We use 2 space indent to match JSON style guide.
+          'indent': 2 if opt.pretty else None,
+          'separators': (',', ': ') if opt.pretty else (',', ':'),
+          'sort_keys': True,
+      }
+      fd.write(json.dumps(doc, **json_settings))
+    else:
+      self.manifest.Save(fd,
+                         peg_rev=opt.peg_rev,
+                         peg_rev_upstream=opt.peg_rev_upstream,
+                         peg_rev_dest_branch=opt.peg_rev_dest_branch)
    fd.close()
    if opt.output_file != '-':
      print('Saved manifest to %s' % opt.output_file, file=sys.stderr)
--- a/subcmds/overview.py
+++ b/subcmds/overview.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2012 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 from color import Coloring
 from command import PagedCommand

--- a/subcmds/prune.py
+++ b/subcmds/prune.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 from color import Coloring
 from command import PagedCommand

--- a/subcmds/rebase.py
+++ b/subcmds/rebase.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2010 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 import sys

 from color import Coloring
--- a/subcmds/selfupdate.py
+++ b/subcmds/selfupdate.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2009 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 from optparse import SUPPRESS_HELP
 import sys

--- a/subcmds/smartsync.py
+++ b/subcmds/smartsync.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2010 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
--- a/subcmds/stage.py
+++ b/subcmds/stage.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 import sys

 from color import Coloring
--- a/subcmds/start.py
+++ b/subcmds/start.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 import os
 import sys

--- a/subcmds/status.py
+++ b/subcmds/status.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,19 +12,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
-
+import functools
 import glob
-import itertools
+import multiprocessing
 import os

 from command import PagedCommand

-try:
-  import threading as _threading
-except ImportError:
-  import dummy_threading as _threading
-
 from color import Coloring
 import platform_utils

@ -95,25 +87,20 @@ the following meanings:
    p.add_option('-q', '--quiet', action='store_true',
                 help="only print the name of modified projects")

-  def _StatusHelper(self, project, clean_counter, sem, quiet):
+  def _StatusHelper(self, quiet, project):
    """Obtains the status for a specific project.

    Obtains the status for a project, redirecting the output to
-    the specified object. It will release the semaphore
-    when done.
+    the specified object.

    Args:
+      quiet: Where to output the status.
      project: Project to get status of.
-      clean_counter: Counter for clean projects.
-      sem: Semaphore, will call release() when complete.
-      output: Where to output the status.
+
+    Returns:
+      The status of the project.
    """
-    try:
-      state = project.PrintWorkTreeStatus(quiet=quiet)
-      if state == 'CLEAN':
-        next(clean_counter)
-    finally:
-      sem.release()
+    return project.PrintWorkTreeStatus(quiet=quiet)

  def _FindOrphans(self, dirs, proj_dirs, proj_dirs_parents, outstring):
    """find 'dirs' that are present in 'proj_dirs_parents' but not in 'proj_dirs'"""
@ -133,27 +120,18 @@ the following meanings:

  def Execute(self, opt, args):
    all_projects = self.GetProjects(args)
-    counter = itertools.count()
+    counter = 0

    if opt.jobs == 1:
      for project in all_projects:
        state = project.PrintWorkTreeStatus(quiet=opt.quiet)
        if state == 'CLEAN':
-          next(counter)
+          counter += 1
    else:
-      sem = _threading.Semaphore(opt.jobs)
-      threads = []
-      for project in all_projects:
-        sem.acquire()
-
-        t = _threading.Thread(target=self._StatusHelper,
-                              args=(project, counter, sem, opt.quiet))
-        threads.append(t)
-        t.daemon = True
-        t.start()
-      for t in threads:
-        t.join()
-    if not opt.quiet and len(all_projects) == next(counter):
+      with multiprocessing.Pool(opt.jobs) as pool:
+        states = pool.map(functools.partial(self._StatusHelper, opt.quiet), all_projects)
+        counter += states.count('CLEAN')
+    if not opt.quiet and len(all_projects) == counter:
      print('nothing to commit (working directory clean)')

    if opt.orphans:
@ -183,7 +161,7 @@ the following meanings:
                          proj_dirs, proj_dirs_parents, outstring)

        if outstring:
-          output = StatusColoring(self.manifest.globalConfig)
+          output = StatusColoring(self.client.globalConfig)
          output.project('Objects not within a project (orphans)')
          output.nl()
          for entry in outstring:
--- a/subcmds/sync.py
+++ b/subcmds/sync.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,8 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
-
+import http.cookiejar as cookielib
 import json
 import netrc
 from optparse import SUPPRESS_HELP
@ -26,26 +23,10 @@ import subprocess
 import sys
 import tempfile
 import time
-
-from pyversion import is_python3
-if is_python3():
-  import http.cookiejar as cookielib
-  import urllib.error
-  import urllib.parse
-  import urllib.request
-  import xmlrpc.client
-else:
-  import cookielib
-  import imp
-  import urllib2
-  import urlparse
-  import xmlrpclib
-  urllib = imp.new_module('urllib')
-  urllib.error = urllib2
-  urllib.parse = urlparse
-  urllib.request = urllib2
-  xmlrpc = imp.new_module('xmlrpc')
-  xmlrpc.client = xmlrpclib
+import urllib.error
+import urllib.parse
+import urllib.request
+import xmlrpc.client

 try:
  import threading as _threading
@ -138,11 +119,11 @@ if the manifest server specified in the manifest file already includes
 credentials.

 By default, all projects will be synced. The --fail-fast option can be used
-to halt syncing as soon as possible when the the first project fails to sync.
+to halt syncing as soon as possible when the first project fails to sync.

 The --force-sync option can be used to overwrite existing git
 directories if they have previously been linked to a different
-object direcotry. WARNING: This may cause data to be lost since
+object directory. WARNING: This may cause data to be lost since
 refs may be removed when overwriting.

 The --force-remove-dirty option can be used to remove previously used
@ -247,8 +228,9 @@ later is required to fix a server side protocol bug.
    p.add_option('-m', '--manifest-name',
                 dest='manifest_name',
                 help='temporary manifest to use for this sync', metavar='NAME.xml')
-    p.add_option('--no-clone-bundle',
-                 dest='clone_bundle', default=True, action='store_false',
+    p.add_option('--clone-bundle', action='store_true',
+                 help='enable use of /clone.bundle on HTTP/HTTPS')
+    p.add_option('--no-clone-bundle', dest='clone_bundle', action='store_false',
                 help='disable use of /clone.bundle on HTTP/HTTPS')
    p.add_option('-u', '--manifest-server-username', action='store',
                 dest='manifest_server_username',
@ -779,6 +761,7 @@ later is required to fix a server side protocol bug.
      start = time.time()
      success = mp.Sync_NetworkHalf(quiet=opt.quiet, verbose=opt.verbose,
                                    current_branch_only=opt.current_branch_only,
+                                    force_sync=opt.force_sync,
                                    tags=opt.tags,
                                    optimized_fetch=opt.optimized_fetch,
                                    retry_fetches=opt.retry_fetches,
@ -836,6 +819,9 @@ later is required to fix a server side protocol bug.
    smart_sync_manifest_path = os.path.join(
        self.manifest.manifestProject.worktree, 'smart_sync_override.xml')

+    if opt.clone_bundle is None:
+      opt.clone_bundle = self.manifest.CloneBundle
+
    if opt.smart_sync or opt.smart_tag:
      manifest_name = self._SmartSyncSetup(opt, smart_sync_manifest_path)
    else:
--- a/subcmds/upload.py
+++ b/subcmds/upload.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2008 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,22 +12,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 import copy
 import re
 import sys

 from command import InteractiveCommand
 from editor import Editor
-from error import HookError, UploadError
+from error import UploadError
 from git_command import GitCommand
-from project import RepoHook
+from git_refs import R_HEADS
+from hooks import RepoHook

-from pyversion import is_python3
-if not is_python3():
-  input = raw_input  # noqa: F821
-else:
-  unicode = str

 UNUSUAL_COMMIT_THRESHOLD = 5

@ -204,33 +197,7 @@ Gerrit Code Review:  https://www.gerritcodereview.com/
    p.add_option('--no-cert-checks',
                 dest='validate_certs', action='store_false', default=True,
                 help='Disable verifying ssl certs (unsafe).')
-
-    # Options relating to upload hook.  Note that verify and no-verify are NOT
-    # opposites of each other, which is why they store to different locations.
-    # We are using them to match 'git commit' syntax.
-    #
-    # Combinations:
-    # - no-verify=False, verify=False (DEFAULT):
-    #   If stdout is a tty, can prompt about running upload hooks if needed.
-    #   If user denies running hooks, the upload is cancelled.  If stdout is
-    #   not a tty and we would need to prompt about upload hooks, upload is
-    #   cancelled.
-    # - no-verify=False, verify=True:
-    #   Always run upload hooks with no prompt.
-    # - no-verify=True, verify=False:
-    #   Never run upload hooks, but upload anyway (AKA bypass hooks).
-    # - no-verify=True, verify=True:
-    #   Invalid
-    g = p.add_option_group('Upload hooks')
-    g.add_option('--no-verify',
-                 dest='bypass_hooks', action='store_true',
-                 help='Do not run the upload hook.')
-    g.add_option('--verify',
-                 dest='allow_all_hooks', action='store_true',
-                 help='Run the upload hook without prompting.')
-    g.add_option('--ignore-hooks',
-                 dest='ignore_hooks', action='store_true',
-                 help='Do not abort uploading if upload hooks fail.')
+    RepoHook.AddOptionGroup(p, 'pre-upload')

  def _SingleBranch(self, opt, branch, people):
    project = branch.project
@ -462,7 +429,10 @@ Gerrit Code Review:  https://www.gerritcodereview.com/
        # Make sure our local branch is not setup to track a different remote branch
        merge_branch = self._GetMergeBranch(branch.project)
        if destination:
-          full_dest = 'refs/heads/%s' % destination
+          full_dest = destination
+          if not full_dest.startswith(R_HEADS):
+            full_dest = R_HEADS + full_dest
+
          if not opt.dest_branch and merge_branch and merge_branch != full_dest:
            print('merge branch %s does not match destination branch %s'
                  % (merge_branch, full_dest))
@ -550,10 +520,10 @@ Gerrit Code Review:  https://www.gerritcodereview.com/
          avail = [up_branch]
        else:
          avail = None
-          print('ERROR: Current branch (%s) not uploadable. '
-                'You may be able to type '
-                '"git branch --set-upstream-to m/master" to fix '
-                'your branch.' % str(cbr),
+          print('repo: error: Unable to upload branch "%s". '
+                'You might be able to fix the branch by running:\n'
+                '  git branch --set-upstream-to m/%s' %
+                (str(cbr), self.manifest.branch),
                file=sys.stderr)
      else:
        avail = project.GetUploadableBranches(branch)
@ -568,31 +538,15 @@ Gerrit Code Review:  https://www.gerritcodereview.com/
              (branch,), file=sys.stderr)
      return 1

-    if not opt.bypass_hooks:
-      hook = RepoHook('pre-upload', self.manifest.repo_hooks_project,
-                      self.manifest.topdir,
-                      self.manifest.manifestProject.GetRemote('origin').url,
-                      abort_if_user_denies=True)
-      pending_proj_names = [project.name for (project, available) in pending]
-      pending_worktrees = [project.worktree for (project, available) in pending]
-      passed = True
-      try:
-        hook.Run(opt.allow_all_hooks, project_list=pending_proj_names,
-                 worktree_list=pending_worktrees)
-      except SystemExit:
-        passed = False
-        if not opt.ignore_hooks:
-          raise
-      except HookError as e:
-        passed = False
-        print("ERROR: %s" % str(e), file=sys.stderr)
-
-      if not passed:
-        if opt.ignore_hooks:
-          print('\nWARNING: pre-upload hooks failed, but uploading anyways.',
-                file=sys.stderr)
-        else:
-          return
+    pending_proj_names = [project.name for (project, available) in pending]
+    pending_worktrees = [project.worktree for (project, available) in pending]
+    hook = RepoHook.FromSubcmd(
+        hook_type='pre-upload', manifest=self.manifest,
+        opt=opt, abort_if_user_denies=True)
+    if not hook.Run(
+        project_list=pending_proj_names,
+        worktree_list=pending_worktrees):
+      return 1

    if opt.reviewers:
      reviewers = _SplitEmails(opt.reviewers)
--- a/subcmds/version.py
+++ b/subcmds/version.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2009 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,8 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
-
 import platform
 import sys

--- a/tests/test_editor.py
+++ b/tests/test_editor.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2019 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -16,8 +14,6 @@

 """Unittests for the editor.py module."""

-from __future__ import print_function
-
 import unittest

 from editor import Editor
--- a/tests/test_git_command.py
+++ b/tests/test_git_command.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright 2019 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -16,8 +14,6 @@

 """Unittests for the git_command.py module."""

-from __future__ import print_function
-
 import re
 import unittest

--- a/tests/test_git_config.py
+++ b/tests/test_git_config.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2009 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -16,8 +14,6 @@

 """Unittests for the git_config.py module."""

-from __future__ import print_function
-
 import os
 import unittest

--- a/tests/test_git_trace2_event_log.py
+++ b/tests/test_git_trace2_event_log.py
@ -0,0 +1,186 @@
+# Copyright (C) 2020 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Unittests for the git_trace2_event_log.py module."""
+
+import json
+import os
+import tempfile
+import unittest
+from unittest import mock
+
+import git_trace2_event_log
+
+
+class EventLogTestCase(unittest.TestCase):
+  """TestCase for the EventLog module."""
+
+  PARENT_SID_KEY = 'GIT_TRACE2_PARENT_SID'
+  PARENT_SID_VALUE = 'parent_sid'
+  SELF_SID_REGEX = r'repo-\d+T\d+Z-.*'
+  FULL_SID_REGEX = r'^%s/%s' % (PARENT_SID_VALUE, SELF_SID_REGEX)
+
+  def setUp(self):
+    """Load the event_log module every time."""
+    self._event_log_module = None
+    # By default we initialize with the expected case where
+    # repo launches us (so GIT_TRACE2_PARENT_SID is set).
+    env = {
+        self.PARENT_SID_KEY: self.PARENT_SID_VALUE,
+    }
+    self._event_log_module = git_trace2_event_log.EventLog(env=env)
+    self._log_data = None
+
+  def verifyCommonKeys(self, log_entry, expected_event_name, full_sid=True):
+    """Helper function to verify common event log keys."""
+    self.assertIn('event', log_entry)
+    self.assertIn('sid', log_entry)
+    self.assertIn('thread', log_entry)
+    self.assertIn('time', log_entry)
+
+    # Do basic data format validation.
+    self.assertEqual(expected_event_name, log_entry['event'])
+    if full_sid:
+      self.assertRegex(log_entry['sid'], self.FULL_SID_REGEX)
+    else:
+      self.assertRegex(log_entry['sid'], self.SELF_SID_REGEX)
+    self.assertRegex(log_entry['time'], r'^\d+-\d+-\d+T\d+:\d+:\d+\.\d+Z$')
+
+  def readLog(self, log_path):
+    """Helper function to read log data into a list."""
+    log_data = []
+    with open(log_path, mode='rb') as f:
+      for line in f:
+        log_data.append(json.loads(line))
+    return log_data
+
+  def test_initial_state_with_parent_sid(self):
+    """Test initial state when 'GIT_TRACE2_PARENT_SID' is set by parent."""
+    self.assertRegex(self._event_log_module.full_sid, self.FULL_SID_REGEX)
+
+  def test_initial_state_no_parent_sid(self):
+    """Test initial state when 'GIT_TRACE2_PARENT_SID' is not set."""
+    # Setup an empty environment dict (no parent sid).
+    self._event_log_module = git_trace2_event_log.EventLog(env={})
+    self.assertRegex(self._event_log_module.full_sid, self.SELF_SID_REGEX)
+
+  def test_version_event(self):
+    """Test 'version' event data is valid.
+
+    Verify that the 'version' event is written even when no other
+    events are addded.
+
+    Expected event log:
+    <version event>
+    """
+    with tempfile.TemporaryDirectory(prefix='event_log_tests') as tempdir:
+      log_path = self._event_log_module.Write(path=tempdir)
+      self._log_data = self.readLog(log_path)
+
+    # A log with no added events should only have the version entry.
+    self.assertEqual(len(self._log_data), 1)
+    version_event = self._log_data[0]
+    self.verifyCommonKeys(version_event, expected_event_name='version')
+    # Check for 'version' event specific fields.
+    self.assertIn('evt', version_event)
+    self.assertIn('exe', version_event)
+
+  def test_start_event(self):
+    """Test and validate 'start' event data is valid.
+
+    Expected event log:
+    <version event>
+    <start event>
+    """
+    self._event_log_module.StartEvent()
+    with tempfile.TemporaryDirectory(prefix='event_log_tests') as tempdir:
+      log_path = self._event_log_module.Write(path=tempdir)
+      self._log_data = self.readLog(log_path)
+
+    self.assertEqual(len(self._log_data), 2)
+    start_event = self._log_data[1]
+    self.verifyCommonKeys(self._log_data[0], expected_event_name='version')
+    self.verifyCommonKeys(start_event, expected_event_name='start')
+    # Check for 'start' event specific fields.
+    self.assertIn('argv', start_event)
+    self.assertTrue(isinstance(start_event['argv'], list))
+
+  def test_exit_event_result_none(self):
+    """Test 'exit' event data is valid when result is None.
+
+    We expect None result to be converted to 0 in the exit event data.
+
+    Expected event log:
+    <version event>
+    <exit event>
+    """
+    self._event_log_module.ExitEvent(None)
+    with tempfile.TemporaryDirectory(prefix='event_log_tests') as tempdir:
+      log_path = self._event_log_module.Write(path=tempdir)
+      self._log_data = self.readLog(log_path)
+
+    self.assertEqual(len(self._log_data), 2)
+    exit_event = self._log_data[1]
+    self.verifyCommonKeys(self._log_data[0], expected_event_name='version')
+    self.verifyCommonKeys(exit_event, expected_event_name='exit')
+    # Check for 'exit' event specific fields.
+    self.assertIn('code', exit_event)
+    # 'None' result should convert to 0 (successful) return code.
+    self.assertEqual(exit_event['code'], 0)
+
+  def test_exit_event_result_integer(self):
+    """Test 'exit' event data is valid when result is an integer.
+
+    Expected event log:
+    <version event>
+    <exit event>
+    """
+    self._event_log_module.ExitEvent(2)
+    with tempfile.TemporaryDirectory(prefix='event_log_tests') as tempdir:
+      log_path = self._event_log_module.Write(path=tempdir)
+      self._log_data = self.readLog(log_path)
+
+    self.assertEqual(len(self._log_data), 2)
+    exit_event = self._log_data[1]
+    self.verifyCommonKeys(self._log_data[0], expected_event_name='version')
+    self.verifyCommonKeys(exit_event, expected_event_name='exit')
+    # Check for 'exit' event specific fields.
+    self.assertIn('code', exit_event)
+    self.assertEqual(exit_event['code'], 2)
+
+  def test_write_with_filename(self):
+    """Test Write() with a path to a file exits with None."""
+    self.assertIsNone(self._event_log_module.Write(path='path/to/file'))
+
+  def test_write_with_git_config(self):
+    """Test Write() uses the git config path when 'git config' call succeeds."""
+    with tempfile.TemporaryDirectory(prefix='event_log_tests') as tempdir:
+      with mock.patch.object(self._event_log_module,
+                             '_GetEventTargetPath', return_value=tempdir):
+        self.assertEqual(os.path.dirname(self._event_log_module.Write()), tempdir)
+
+  def test_write_no_git_config(self):
+    """Test Write() with no git config variable present exits with None."""
+    with mock.patch.object(self._event_log_module,
+                           '_GetEventTargetPath', return_value=None):
+      self.assertIsNone(self._event_log_module.Write())
+
+  def test_write_non_string(self):
+    """Test Write() with non-string type for |path| throws TypeError."""
+    with self.assertRaises(TypeError):
+      self._event_log_module.Write(path=1234)
+
+
+if __name__ == '__main__':
+  unittest.main()
--- a/tests/test_hooks.py
+++ b/tests/test_hooks.py
@ -0,0 +1,55 @@
+# Copyright (C) 2019 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Unittests for the hooks.py module."""
+
+import hooks
+import unittest
+
+class RepoHookShebang(unittest.TestCase):
+  """Check shebang parsing in RepoHook."""
+
+  def test_no_shebang(self):
+    """Lines w/out shebangs should be rejected."""
+    DATA = (
+        '',
+        '#\n# foo\n',
+        '# Bad shebang in script\n#!/foo\n'
+    )
+    for data in DATA:
+      self.assertIsNone(hooks.RepoHook._ExtractInterpFromShebang(data))
+
+  def test_direct_interp(self):
+    """Lines whose shebang points directly to the interpreter."""
+    DATA = (
+        ('#!/foo', '/foo'),
+        ('#! /foo', '/foo'),
+        ('#!/bin/foo ', '/bin/foo'),
+        ('#! /usr/foo ', '/usr/foo'),
+        ('#! /usr/foo -args', '/usr/foo'),
+    )
+    for shebang, interp in DATA:
+      self.assertEqual(hooks.RepoHook._ExtractInterpFromShebang(shebang),
+                       interp)
+
+  def test_env_interp(self):
+    """Lines whose shebang launches through `env`."""
+    DATA = (
+        ('#!/usr/bin/env foo', 'foo'),
+        ('#!/bin/env foo', 'foo'),
+        ('#! /bin/env /bin/foo ', '/bin/foo'),
+    )
+    for shebang, interp in DATA:
+      self.assertEqual(hooks.RepoHook._ExtractInterpFromShebang(shebang),
+                       interp)
--- a/tests/test_manifest_xml.py
+++ b/tests/test_manifest_xml.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2019 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -16,9 +14,9 @@

 """Unittests for the manifest_xml.py module."""

-from __future__ import print_function
-
 import os
+import shutil
+import tempfile
 import unittest
 import xml.dom.minidom

@ -146,3 +144,146 @@ class ValueTests(unittest.TestCase):
    with self.assertRaises(error.ManifestParseError):
      node = self._get_node('<node a="xx"/>')
      manifest_xml.XmlInt(node, 'a')
+
+
+class XmlManifestTests(unittest.TestCase):
+  """Check manifest processing."""
+
+  def setUp(self):
+    self.tempdir = tempfile.mkdtemp(prefix='repo_tests')
+    self.repodir = os.path.join(self.tempdir, '.repo')
+    self.manifest_dir = os.path.join(self.repodir, 'manifests')
+    self.manifest_file = os.path.join(
+        self.repodir, manifest_xml.MANIFEST_FILE_NAME)
+    self.local_manifest_dir = os.path.join(
+        self.repodir, manifest_xml.LOCAL_MANIFESTS_DIR_NAME)
+    os.mkdir(self.repodir)
+    os.mkdir(self.manifest_dir)
+
+    # The manifest parsing really wants a git repo currently.
+    gitdir = os.path.join(self.repodir, 'manifests.git')
+    os.mkdir(gitdir)
+    with open(os.path.join(gitdir, 'config'), 'w') as fp:
+      fp.write("""[remote "origin"]
+        url = https://localhost:0/manifest
+""")
+
+  def tearDown(self):
+    shutil.rmtree(self.tempdir, ignore_errors=True)
+
+  def getXmlManifest(self, data):
+    """Helper to initialize a manifest for testing."""
+    with open(self.manifest_file, 'w') as fp:
+      fp.write(data)
+    return manifest_xml.XmlManifest(self.repodir, self.manifest_file)
+
+  def test_empty(self):
+    """Parse an 'empty' manifest file."""
+    manifest = self.getXmlManifest(
+        '<?xml version="1.0" encoding="UTF-8"?>'
+        '<manifest></manifest>')
+    self.assertEqual(manifest.remotes, {})
+    self.assertEqual(manifest.projects, [])
+
+  def test_link(self):
+    """Verify Link handling with new names."""
+    manifest = manifest_xml.XmlManifest(self.repodir, self.manifest_file)
+    with open(os.path.join(self.manifest_dir, 'foo.xml'), 'w') as fp:
+      fp.write('<manifest></manifest>')
+    manifest.Link('foo.xml')
+    with open(self.manifest_file) as fp:
+      self.assertIn('<include name="foo.xml" />', fp.read())
+
+  def test_toxml_empty(self):
+    """Verify the ToXml() helper."""
+    manifest = self.getXmlManifest(
+        '<?xml version="1.0" encoding="UTF-8"?>'
+        '<manifest></manifest>')
+    self.assertEqual(manifest.ToXml().toxml(), '<?xml version="1.0" ?><manifest/>')
+
+  def test_todict_empty(self):
+    """Verify the ToDict() helper."""
+    manifest = self.getXmlManifest(
+        '<?xml version="1.0" encoding="UTF-8"?>'
+        '<manifest></manifest>')
+    self.assertEqual(manifest.ToDict(), {})
+
+  def test_repo_hooks(self):
+    """Check repo-hooks settings."""
+    manifest = self.getXmlManifest("""
+<manifest>
+  <remote name="test-remote" fetch="http://localhost" />
+  <default remote="test-remote" revision="refs/heads/main" />
+  <project name="repohooks" path="src/repohooks"/>
+  <repo-hooks in-project="repohooks" enabled-list="a, b"/>
+</manifest>
+""")
+    self.assertEqual(manifest.repo_hooks_project.name, 'repohooks')
+    self.assertEqual(manifest.repo_hooks_project.enabled_repo_hooks, ['a', 'b'])
+
+  def test_project_group(self):
+    """Check project group settings."""
+    manifest = self.getXmlManifest("""
+<manifest>
+  <remote name="test-remote" fetch="http://localhost" />
+  <default remote="test-remote" revision="refs/heads/main" />
+  <project name="test-name" path="test-path"/>
+  <project name="extras" path="path" groups="g1,g2,g1"/>
+</manifest>
+""")
+    self.assertEqual(len(manifest.projects), 2)
+    # Ordering isn't guaranteed.
+    result = {
+        manifest.projects[0].name: manifest.projects[0].groups,
+        manifest.projects[1].name: manifest.projects[1].groups,
+    }
+    project = manifest.projects[0]
+    self.assertCountEqual(
+        result['test-name'],
+        ['name:test-name', 'all', 'path:test-path'])
+    self.assertCountEqual(
+        result['extras'],
+        ['g1', 'g2', 'g1', 'name:extras', 'all', 'path:path'])
+
+  def test_include_levels(self):
+    root_m = os.path.join(self.manifest_dir, 'root.xml')
+    with open(root_m, 'w') as fp:
+      fp.write("""
+<manifest>
+  <remote name="test-remote" fetch="http://localhost" />
+  <default remote="test-remote" revision="refs/heads/main" />
+  <include name="level1.xml" groups="level1-group" />
+  <project name="root-name1" path="root-path1" />
+  <project name="root-name2" path="root-path2" groups="r2g1,r2g2" />
+</manifest>
+""")
+    with open(os.path.join(self.manifest_dir, 'level1.xml'), 'w') as fp:
+      fp.write("""
+<manifest>
+  <include name="level2.xml" groups="level2-group" />
+  <project name="level1-name1" path="level1-path1" />
+</manifest>
+""")
+    with open(os.path.join(self.manifest_dir, 'level2.xml'), 'w') as fp:
+      fp.write("""
+<manifest>
+  <project name="level2-name1" path="level2-path1" groups="l2g1,l2g2" />
+</manifest>
+""")
+    include_m = manifest_xml.XmlManifest(self.repodir, root_m)
+    for proj in include_m.projects:
+      if proj.name == 'root-name1':
+        # Check include group not set on root level proj.
+        self.assertNotIn('level1-group', proj.groups)
+      if proj.name == 'root-name2':
+        # Check root proj group not removed.
+        self.assertIn('r2g1', proj.groups)
+      if proj.name == 'level1-name1':
+        # Check level1 proj has inherited group level 1.
+        self.assertIn('level1-group', proj.groups)
+      if proj.name == 'level2-name1':
+        # Check level2 proj has inherited group levels 1 and 2.
+        self.assertIn('level1-group', proj.groups)
+        self.assertIn('level2-group', proj.groups)
+        # Check level2 proj group not removed.
+        self.assertIn('l2g1', proj.groups)
--- a/tests/test_project.py
+++ b/tests/test_project.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2019 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -16,8 +14,6 @@

 """Unittests for the project.py module."""

-from __future__ import print_function
-
 import contextlib
 import os
 import shutil
@ -26,6 +22,7 @@ import tempfile
 import unittest

 import error
+import git_command
 import git_config
 import platform_utils
 import project
@ -38,51 +35,24 @@ def TempGitTree():
  # Python 2 support entirely.
  try:
    tempdir = tempfile.mkdtemp(prefix='repo-tests')
-    subprocess.check_call(['git', 'init'], cwd=tempdir)
+
+    # Tests need to assume, that main is default branch at init,
+    # which is not supported in config until 2.28.
+    cmd = ['git', 'init']
+    if git_command.git_require((2, 28, 0)):
+      cmd += ['--initial-branch=main']
+    else:
+      # Use template dir for init.
+      templatedir = tempfile.mkdtemp(prefix='.test-template')
+      with open(os.path.join(templatedir, 'HEAD'), 'w') as fp:
+        fp.write('ref: refs/heads/main\n')
+      cmd += ['--template=', templatedir]
+    subprocess.check_call(cmd, cwd=tempdir)
    yield tempdir
  finally:
    platform_utils.rmtree(tempdir)


-class RepoHookShebang(unittest.TestCase):
-  """Check shebang parsing in RepoHook."""
-
-  def test_no_shebang(self):
-    """Lines w/out shebangs should be rejected."""
-    DATA = (
-        '',
-        '# -*- coding:utf-8 -*-\n',
-        '#\n# foo\n',
-        '# Bad shebang in script\n#!/foo\n'
-    )
-    for data in DATA:
-      self.assertIsNone(project.RepoHook._ExtractInterpFromShebang(data))
-
-  def test_direct_interp(self):
-    """Lines whose shebang points directly to the interpreter."""
-    DATA = (
-        ('#!/foo', '/foo'),
-        ('#! /foo', '/foo'),
-        ('#!/bin/foo ', '/bin/foo'),
-        ('#! /usr/foo ', '/usr/foo'),
-        ('#! /usr/foo -args', '/usr/foo'),
-    )
-    for shebang, interp in DATA:
-      self.assertEqual(project.RepoHook._ExtractInterpFromShebang(shebang),
-                       interp)
-
-  def test_env_interp(self):
-    """Lines whose shebang launches through `env`."""
-    DATA = (
-        ('#!/usr/bin/env foo', 'foo'),
-        ('#!/bin/env foo', 'foo'),
-        ('#! /bin/env /bin/foo ', '/bin/foo'),
-    )
-    for shebang, interp in DATA:
-      self.assertEqual(project.RepoHook._ExtractInterpFromShebang(shebang),
-                       interp)
-
-
 class FakeProject(object):
  """A fake for Project for basic functionality."""

@ -116,7 +86,7 @@ class ReviewableBranchTests(unittest.TestCase):

      # Start off with the normal details.
      rb = project.ReviewableBranch(
-          fakeproj, fakeproj.config.GetBranch('work'), 'master')
+          fakeproj, fakeproj.config.GetBranch('work'), 'main')
      self.assertEqual('work', rb.name)
      self.assertEqual(1, len(rb.commits))
      self.assertIn('Del file', rb.commits[0])
@ -129,9 +99,9 @@ class ReviewableBranchTests(unittest.TestCase):
      self.assertTrue(rb.date)

      # Now delete the tracking branch!
-      fakeproj.work_git.branch('-D', 'master')
+      fakeproj.work_git.branch('-D', 'main')
      rb = project.ReviewableBranch(
-          fakeproj, fakeproj.config.GetBranch('work'), 'master')
+          fakeproj, fakeproj.config.GetBranch('work'), 'main')
      self.assertEqual(0, len(rb.commits))
      self.assertFalse(rb.base_exists)
      # Hard to assert anything useful about this.
--- a/tests/test_subcmds.py
+++ b/tests/test_subcmds.py
@ -0,0 +1,43 @@
+# Copyright (C) 2020 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Unittests for the subcmds module (mostly __init__.py than subcommands)."""
+
+import unittest
+
+import subcmds
+
+
+class AllCommands(unittest.TestCase):
+  """Check registered all_commands."""
+
+  def test_required_basic(self):
+    """Basic checking of registered commands."""
+    # NB: We don't test all subcommands as we want to avoid "change detection"
+    # tests, so we just look for the most common/important ones here that are
+    # unlikely to ever change.
+    for cmd in {'cherry-pick', 'help', 'init', 'start', 'sync', 'upload'}:
+      self.assertIn(cmd, subcmds.all_commands)
+
+  def test_naming(self):
+    """Verify we don't add things that we shouldn't."""
+    for cmd in subcmds.all_commands:
+      # Reject filename suffixes like "help.py".
+      self.assertNotIn('.', cmd)
+
+      # Make sure all '_' were converted to '-'.
+      self.assertNotIn('_', cmd)
+
+      # Reject internal python paths like "__init__".
+      self.assertFalse(cmd.startswith('__'))
--- a/tests/test_subcmds_init.py
+++ b/tests/test_subcmds_init.py
@ -0,0 +1,49 @@
+# Copyright (C) 2020 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Unittests for the subcmds/init.py module."""
+
+import unittest
+
+from subcmds import init
+
+
+class InitCommand(unittest.TestCase):
+  """Check registered all_commands."""
+
+  def setUp(self):
+    self.cmd = init.Init()
+
+  def test_cli_parser_good(self):
+    """Check valid command line options."""
+    ARGV = (
+        [],
+    )
+    for argv in ARGV:
+      opts, args = self.cmd.OptionParser.parse_args(argv)
+      self.cmd.ValidateOptions(opts, args)
+
+  def test_cli_parser_bad(self):
+    """Check invalid command line options."""
+    ARGV = (
+        # Too many arguments.
+        ['asdf'],
+
+        # Conflicting options.
+        ['--mirror', '--archive'],
+    )
+    for argv in ARGV:
+      opts, args = self.cmd.OptionParser.parse_args(argv)
+      with self.assertRaises(SystemExit):
+        self.cmd.ValidateOptions(opts, args)
--- a/tests/test_wrapper.py
+++ b/tests/test_wrapper.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2015 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -16,28 +14,21 @@

 """Unittests for the wrapper.py module."""

-from __future__ import print_function
-
 import contextlib
+from io import StringIO
 import os
 import re
 import shutil
 import tempfile
 import unittest
+from unittest import mock

+import git_command
+import main
 import platform_utils
-from pyversion import is_python3
 import wrapper


-if is_python3():
-  from unittest import mock
-  from io import StringIO
-else:
-  import mock
-  from StringIO import StringIO
-
-
@contextlib.contextmanager
 def TemporaryDirectory():
  """Create a new empty git checkout for testing."""
@ -64,9 +55,6 @@ class RepoWrapperTestCase(unittest.TestCase):
    wrapper._wrapper_module = None
    self.wrapper = wrapper.Wrapper()

-    if not is_python3():
-      self.assertRegex = self.assertRegexpMatches
-

 class RepoWrapperUnitTest(RepoWrapperTestCase):
  """Tests helper functions in the repo wrapper
@ -82,6 +70,16 @@ class RepoWrapperUnitTest(RepoWrapperTestCase):
    self.assertEqual('', stderr.getvalue())
    self.assertIn('repo launcher version', stdout.getvalue())

+  def test_python_constraints(self):
+    """The launcher should never require newer than main.py."""
+    self.assertGreaterEqual(main.MIN_PYTHON_VERSION_HARD,
+                            wrapper.MIN_PYTHON_VERSION_HARD)
+    self.assertGreaterEqual(main.MIN_PYTHON_VERSION_SOFT,
+                            wrapper.MIN_PYTHON_VERSION_SOFT)
+    # Make sure the versions are themselves in sync.
+    self.assertGreaterEqual(wrapper.MIN_PYTHON_VERSION_SOFT,
+                            wrapper.MIN_PYTHON_VERSION_HARD)
+
  def test_init_parser(self):
    """Make sure 'init' GetParser works."""
    parser = self.wrapper.GetParser(gitc_init=False)
@ -357,7 +355,19 @@ class GitCheckoutTestCase(RepoWrapperTestCase):

    remote = os.path.join(cls.GIT_DIR, 'remote')
    os.mkdir(remote)
-    run_git('init', cwd=remote)
+
+    # Tests need to assume, that main is default branch at init,
+    # which is not supported in config until 2.28.
+    if git_command.git_require((2, 28, 0)):
+      initstr = '--initial-branch=main'
+    else:
+      # Use template dir for init.
+      templatedir = tempfile.mkdtemp(prefix='.test-template')
+      with open(os.path.join(templatedir, 'HEAD'), 'w') as fp:
+        fp.write('ref: refs/heads/main\n')
+      initstr = '--template=' + templatedir
+
+    run_git('init', initstr, cwd=remote)
    run_git('commit', '--allow-empty', '-minit', cwd=remote)
    run_git('branch', 'stable', cwd=remote)
    run_git('tag', 'v1.0', cwd=remote)
@ -402,8 +412,8 @@ class ResolveRepoRev(GitCheckoutTestCase):
    self.assertEqual('refs/heads/stable', rrev)
    self.assertEqual(self.REV_LIST[1], lrev)

-    rrev, lrev = self.wrapper.resolve_repo_rev(self.GIT_DIR, 'master')
-    self.assertEqual('refs/heads/master', rrev)
+    rrev, lrev = self.wrapper.resolve_repo_rev(self.GIT_DIR, 'main')
+    self.assertEqual('refs/heads/main', rrev)
    self.assertEqual(self.REV_LIST[0], lrev)

  def test_tag_name(self):
--- a/tox.ini
+++ b/tox.ini
@ -15,11 +15,10 @@
 # https://tox.readthedocs.io/

 [tox]
-envlist = py27, py36, py37, py38
+envlist = py36, py37, py38

 [gh-actions]
 python =
-    2.7: py27
    3.6: py36
    3.7: py37
    3.8: py38
@ -31,8 +30,3 @@ setenv =
    GIT_AUTHOR_NAME = Repo test author
    GIT_COMMITTER_NAME = Repo test committer
    EMAIL = repo@gerrit.nodomain
-
-[testenv:py27]
-deps =
-    mock
-    pytest
--- a/wrapper.py
+++ b/wrapper.py
@ -1,5 +1,3 @@
-# -*- coding:utf-8 -*-
-#
 # Copyright (C) 2014 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@ -14,7 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.

-from __future__ import print_function
 try:
  from importlib.machinery import SourceFileLoader
  _loader = lambda *args: SourceFileLoader(*args).load_module()