trace: restore Progress indicator.

If we are not tracing to stderr, then we should still have progress
indication.

Change-Id: Ifc9678e1fccbd92251e972fcf25aad6369d60e15
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/351195
Reviewed-by: Sam Saccone <samccone@google.com>
Tested-by: LaMont Jones <lamontjones@google.com>
Reviewed-by: Xin Li <delphij@google.com>

docs/manifest-format.md

@@ -105,6 +105,8 @@ following DTD:
   <!ATTLIST extend-project groups CDATA #IMPLIED>
   <!ATTLIST extend-project revision CDATA #IMPLIED>
   <!ATTLIST extend-project remote CDATA #IMPLIED>
+  <!ATTLIST extend-project dest-branch CDATA #IMPLIED>
+  <!ATTLIST extend-project upstream CDATA #IMPLIED>
 
   <!ELEMENT remove-project EMPTY>
   <!ATTLIST remove-project name  CDATA #REQUIRED>
@@ -423,6 +425,12 @@ project.  Same syntax as the corresponding element of `project`.
 Attribute `remote`: If specified, overrides the remote of the original
 project.  Same syntax as the corresponding element of `project`.
 
+Attribute `dest-branch`: If specified, overrides the dest-branch of the original
+project.  Same syntax as the corresponding element of `project`.
+
+Attribute `upstream`: If specified, overrides the upstream of the original
+project.  Same syntax as the corresponding element of `project`.
+
 ### Element annotation
 
 Zero or more annotation elements may be specified as children of a

git_command.py

@@ -230,12 +230,11 @@ class GitCommand(object):
     stderr = (subprocess.STDOUT if merge_output else
               (subprocess.PIPE if capture_stderr else None))
 
+    dbg = ''
     if IsTrace():
       global LAST_CWD
       global LAST_GITDIR
 
-      dbg = ''
-
       if cwd and LAST_CWD != cwd:
         if LAST_GITDIR or LAST_CWD:
           dbg += '\n'
@@ -263,31 +262,31 @@ class GitCommand(object):
         dbg += ' 2>|'
       elif stderr == subprocess.STDOUT:
         dbg += ' 2>&1'
-      Trace('%s', dbg)
 
-    try:
-      p = subprocess.Popen(command,
-                           cwd=cwd,
-                           env=env,
-                           encoding='utf-8',
-                           errors='backslashreplace',
-                           stdin=stdin,
-                           stdout=stdout,
-                           stderr=stderr)
-    except Exception as e:
-      raise GitError('%s: %s' % (command[1], e))
+    with Trace('git command %s %s with debug: %s', LAST_GITDIR, command, dbg):
+      try:
+        p = subprocess.Popen(command,
+                            cwd=cwd,
+                            env=env,
+                            encoding='utf-8',
+                            errors='backslashreplace',
+                            stdin=stdin,
+                            stdout=stdout,
+                            stderr=stderr)
+      except Exception as e:
+        raise GitError('%s: %s' % (command[1], e))
 
-    if ssh_proxy:
-      ssh_proxy.add_client(p)
-
-    self.process = p
-
-    try:
-      self.stdout, self.stderr = p.communicate(input=input)
-    finally:
       if ssh_proxy:
-        ssh_proxy.remove_client(p)
-    self.rc = p.wait()
+        ssh_proxy.add_client(p)
+
+      self.process = p
+
+      try:
+        self.stdout, self.stderr = p.communicate(input=input)
+      finally:
+        if ssh_proxy:
+          ssh_proxy.remove_client(p)
+      self.rc = p.wait()
 
   @staticmethod
   def _GetBasicEnv():

git_config.py

@@ -219,8 +219,8 @@ class GitConfig(object):
     """Set the value(s) for a key.
        Only this configuration file is modified.
 
-       The supplied value should be either a string,
-       or a list of strings (to store multiple values).
+       The supplied value should be either a string, or a list of strings (to
+       store multiple values), or None (to delete the key).
     """
     key = _key(name)
 
@@ -349,9 +349,9 @@ class GitConfig(object):
     except OSError:
       return None
     try:
-      Trace(': parsing %s', self.file)
-      with open(self._json) as fd:
-        return json.load(fd)
+      with Trace(': parsing %s', self.file):
+        with open(self._json) as fd:
+          return json.load(fd)
     except (IOError, ValueError):
       platform_utils.remove(self._json, missing_ok=True)
       return None

git_refs.py

@@ -67,38 +67,37 @@ class GitRefs(object):
       self._LoadAll()
 
   def _NeedUpdate(self):
-    Trace(': scan refs %s', self._gitdir)
-
-    for name, mtime in self._mtime.items():
-      try:
-        if mtime != os.path.getmtime(os.path.join(self._gitdir, name)):
+    with Trace(': scan refs %s', self._gitdir):
+      for name, mtime in self._mtime.items():
+        try:
+          if mtime != os.path.getmtime(os.path.join(self._gitdir, name)):
+            return True
+        except OSError:
           return True
-      except OSError:
-        return True
-    return False
+      return False
 
   def _LoadAll(self):
-    Trace(': load refs %s', self._gitdir)
+    with Trace(': load refs %s', self._gitdir):
 
-    self._phyref = {}
-    self._symref = {}
-    self._mtime = {}
+      self._phyref = {}
+      self._symref = {}
+      self._mtime = {}
 
-    self._ReadPackedRefs()
-    self._ReadLoose('refs/')
-    self._ReadLoose1(os.path.join(self._gitdir, HEAD), HEAD)
+      self._ReadPackedRefs()
+      self._ReadLoose('refs/')
+      self._ReadLoose1(os.path.join(self._gitdir, HEAD), HEAD)
 
-    scan = self._symref
-    attempts = 0
-    while scan and attempts < 5:
-      scan_next = {}
-      for name, dest in scan.items():
-        if dest in self._phyref:
-          self._phyref[name] = self._phyref[dest]
-        else:
-          scan_next[name] = dest
-      scan = scan_next
-      attempts += 1
+      scan = self._symref
+      attempts = 0
+      while scan and attempts < 5:
+        scan_next = {}
+        for name, dest in scan.items():
+          if dest in self._phyref:
+            self._phyref[name] = self._phyref[dest]
+          else:
+            scan_next[name] = dest
+        scan = scan_next
+        attempts += 1
 
   def _ReadPackedRefs(self):
     path = os.path.join(self._gitdir, 'packed-refs')

main.py

@@ -37,7 +37,7 @@ except ImportError:
 
 from color import SetDefaultColoring
 import event_log
-from repo_trace import SetTrace
+from repo_trace import SetTrace, Trace, SetTraceToStderr
 from git_command import user_agent
 from git_config import RepoConfig
 from git_trace2_event_log import EventLog
@@ -109,6 +109,9 @@ global_options.add_option('--color',
 global_options.add_option('--trace',
                           dest='trace', action='store_true',
                           help='trace git command execution (REPO_TRACE=1)')
+global_options.add_option('--trace-to-stderr',
+                          dest='trace_to_stderr', action='store_true',
+                          help='trace outputs go to stderr in addition to .repo/TRACE_FILE')
 global_options.add_option('--trace-python',
                           dest='trace_python', action='store_true',
                           help='trace python command execution')
@@ -198,9 +201,6 @@ class _Repo(object):
     """Execute the requested subcommand."""
     result = 0
 
-    if gopts.trace:
-      SetTrace()
-
     # Handle options that terminate quickly first.
     if gopts.help or gopts.help_all:
       self._PrintHelp(short=False, all_commands=gopts.help_all)
@@ -216,6 +216,21 @@ class _Repo(object):
       self._PrintHelp(short=True)
       return 1
 
+    run = lambda: self._RunLong(name, gopts, argv) or 0
+    with Trace('starting new command: %s', ', '.join([name] + argv),
+               first_trace=True):
+      if gopts.trace_python:
+        import trace
+        tracer = trace.Trace(count=False, trace=True, timing=True,
+                             ignoredirs=set(sys.path[1:]))
+        result = tracer.runfunc(run)
+      else:
+        result = run()
+    return result
+
+  def _RunLong(self, name, gopts, argv):
+    """Execute the (longer running) requested subcommand."""
+    result = 0
     SetDefaultColoring(gopts.color)
 
     git_trace2_event_log = EventLog()
@@ -652,17 +667,18 @@ def _Main(argv):
   Version.wrapper_path = opt.wrapper_path
 
   repo = _Repo(opt.repodir)
+
   try:
     init_http()
     name, gopts, argv = repo._ParseArgs(argv)
-    run = lambda: repo._Run(name, gopts, argv) or 0
-    if gopts.trace_python:
-      import trace
-      tracer = trace.Trace(count=False, trace=True, timing=True,
-                           ignoredirs=set(sys.path[1:]))
-      result = tracer.runfunc(run)
-    else:
-      result = run()
+
+    if gopts.trace:
+      SetTrace()
+
+    if gopts.trace_to_stderr:
+      SetTraceToStderr()
+
+    result = repo._Run(name, gopts, argv) or 0
   except KeyboardInterrupt:
     print('aborted by user', file=sys.stderr)
     result = 1

man/repo-gitc-init.1

@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man.
-.TH REPO "1" "August 2022" "repo gitc-init" "Repo Manual"
+.TH REPO "1" "October 2022" "repo gitc-init" "Repo Manual"
 .SH NAME
 repo \- repo gitc-init - manual page for repo gitc-init
 .SH SYNOPSIS
@@ -48,7 +48,7 @@ create a git checkout of the manifest repo
 .TP
 \fB\-\-manifest\-depth\fR=\fI\,DEPTH\/\fR
 create a shallow clone of the manifest repo with given
-depth; see git clone (default: 1)
+depth (0 for full clone); see git clone (default: 0)
 .SS Manifest (only) checkout options:
 .TP
 \fB\-\-current\-branch\fR

man/repo-init.1

@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man.
-.TH REPO "1" "August 2022" "repo init" "Repo Manual"
+.TH REPO "1" "October 2022" "repo init" "Repo Manual"
 .SH NAME
 repo \- repo init - manual page for repo init
 .SH SYNOPSIS
@@ -48,7 +48,7 @@ create a git checkout of the manifest repo
 .TP
 \fB\-\-manifest\-depth\fR=\fI\,DEPTH\/\fR
 create a shallow clone of the manifest repo with given
-depth; see git clone (default: 1)
+depth (0 for full clone); see git clone (default: 0)
 .SS Manifest (only) checkout options:
 .TP
 \fB\-c\fR, \fB\-\-current\-branch\fR

man/repo-manifest.1

@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man.
-.TH REPO "1" "July 2022" "repo manifest" "Repo Manual"
+.TH REPO "1" "October 2022" "repo manifest" "Repo Manual"
 .SH NAME
 repo \- repo manifest - manual page for repo manifest
 .SH SYNOPSIS
@@ -190,6 +190,8 @@ CDATA #IMPLIED>
 <!ATTLIST extend\-project groups CDATA #IMPLIED>
 <!ATTLIST extend\-project revision CDATA #IMPLIED>
 <!ATTLIST extend\-project remote CDATA #IMPLIED>
+<!ATTLIST extend\-project dest\-branch CDATA #IMPLIED>
+<!ATTLIST extend\-project upstream CDATA #IMPLIED>
 .IP
 <!ELEMENT remove\-project EMPTY>
 <!ATTLIST remove\-project name  CDATA #REQUIRED>
@@ -485,6 +487,12 @@ project. Same syntax as the corresponding element of `project`.
 Attribute `remote`: If specified, overrides the remote of the original project.
 Same syntax as the corresponding element of `project`.
 .PP
+Attribute `dest\-branch`: If specified, overrides the dest\-branch of the original
+project. Same syntax as the corresponding element of `project`.
+.PP
+Attribute `upstream`: If specified, overrides the upstream of the original
+project. Same syntax as the corresponding element of `project`.
+.PP
 Element annotation
 .PP
 Zero or more annotation elements may be specified as children of a project or
@@ -600,7 +608,7 @@ included manifest belong. This appends and recurses, meaning all projects in
 included manifests carry all parent include groups. Same syntax as the
 corresponding element of `project`.
 .PP
-Local Manifests
+Local Manifests 
 .PP
 Additional remotes and projects may be added through local manifest files stored
 in `$TOP_DIR/.repo/local_manifests/*.xml`.

man/repo-smartsync.1

@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man.
-.TH REPO "1" "August 2022" "repo smartsync" "Repo Manual"
+.TH REPO "1" "November 2022" "repo smartsync" "Repo Manual"
 .SH NAME
 repo \- repo smartsync - manual page for repo smartsync
 .SH SYNOPSIS
@@ -105,6 +105,13 @@ delete refs that no longer exist on the remote
 .TP
 \fB\-\-no\-prune\fR
 do not delete refs that no longer exist on the remote
+.TP
+\fB\-\-auto\-gc\fR
+run garbage collection on all synced projects
+.TP
+\fB\-\-no\-auto\-gc\fR
+do not run garbage collection on any projects
+(default)
 .SS Logging options:
 .TP
 \fB\-v\fR, \fB\-\-verbose\fR

man/repo-sync.1

@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man.
-.TH REPO "1" "August 2022" "repo sync" "Repo Manual"
+.TH REPO "1" "November 2022" "repo sync" "Repo Manual"
 .SH NAME
 repo \- repo sync - manual page for repo sync
 .SH SYNOPSIS
@@ -106,6 +106,13 @@ delete refs that no longer exist on the remote
 \fB\-\-no\-prune\fR
 do not delete refs that no longer exist on the remote
 .TP
+\fB\-\-auto\-gc\fR
+run garbage collection on all synced projects
+.TP
+\fB\-\-no\-auto\-gc\fR
+do not run garbage collection on any projects
+(default)
+.TP
 \fB\-s\fR, \fB\-\-smart\-sync\fR
 smart sync using manifest from the latest known good
 build
@@ -200,6 +207,9 @@ to a sha1 revision if the sha1 revision does not already exist locally.
 The \fB\-\-prune\fR option can be used to remove any refs that no longer exist on the
 remote.
 .PP
+The \fB\-\-auto\-gc\fR option can be used to trigger garbage collection on all projects.
+By default, repo does not run garbage collection.
+.PP
 SSH Connections
 .PP
 If at least one project remote URL uses an SSH connection (ssh://, git+ssh://,

man/repo.1

@@ -1,5 +1,5 @@
 .\" DO NOT MODIFY THIS FILE!  It was generated by help2man.
-.TH REPO "1" "July 2022" "repo" "Repo Manual"
+.TH REPO "1" "November 2022" "repo" "Repo Manual"
 .SH NAME
 repo \- repository management tool built on top of git
 .SH SYNOPSIS
@@ -25,6 +25,10 @@ control color usage: auto, always, never
 \fB\-\-trace\fR
 trace git command execution (REPO_TRACE=1)
 .TP
+\fB\-\-trace-to-stderr\fR
+trace outputs go to stderr in addition to
+\&.repo/TRACE_FILE
+.TP
 \fB\-\-trace\-python\fR
 trace python command execution
 .TP

manifest_xml.py

@@ -1289,6 +1289,8 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
           remote = self._default.remote
         else:
           remote = self._get_remote(node)
+        dest_branch = node.getAttribute('dest-branch')
+        upstream = node.getAttribute('upstream')
 
         named_projects = self._projects[name]
         if dest_path and not path and len(named_projects) > 1:
@@ -1304,6 +1306,10 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
 
           if remote_name:
             p.remote = remote.ToRemoteSpec(name)
+          if dest_branch:
+            p.dest_branch = dest_branch
+          if upstream:
+            p.upstream = upstream
 
           if dest_path:
             del self._paths[p.relpath]
@@ -1940,11 +1946,14 @@ https://gerrit.googlesource.com/git-repo/+/HEAD/docs/manifest-format.md
     fromKeys = sorted(fromProjects.keys())
     toKeys = sorted(toProjects.keys())
 
-    diff = {'added': [], 'removed': [], 'changed': [], 'unreachable': []}
+    diff = {'added': [], 'removed': [], 'missing': [], 'changed': [], 'unreachable': []}
 
     for proj in fromKeys:
       if proj not in toKeys:
         diff['removed'].append(fromProjects[proj])
+      elif not fromProjects[proj].Exists:
+        diff['missing'].append(toProjects[proj])
+        toKeys.remove(proj)
       else:
         fromProj = fromProjects[proj]
         toProj = toProjects[proj]

progress.py

@@ -15,7 +15,7 @@
 import os
 import sys
 from time import time
-from repo_trace import IsTrace
+from repo_trace import IsTraceToStderr
 
 _NOT_TTY = not os.isatty(2)
 
@@ -80,7 +80,7 @@ class Progress(object):
   def update(self, inc=1, msg=''):
     self._done += inc
 
-    if _NOT_TTY or IsTrace():
+    if _NOT_TTY or IsTraceToStderr():
       return
 
     if not self._show:
@@ -113,7 +113,7 @@ class Progress(object):
       sys.stderr.flush()
 
   def end(self):
-    if _NOT_TTY or IsTrace() or not self._show:
+    if _NOT_TTY or IsTraceToStderr() or not self._show:
       return
 
     duration = duration_str(time() - self._start)

project.py

@@ -26,6 +26,7 @@ import sys
 import tarfile
 import tempfile
 import time
+from typing import NamedTuple
 import urllib.parse
 
 from color import Coloring
@@ -40,17 +41,25 @@ from error import ManifestInvalidRevisionError, ManifestInvalidPathError
 from error import NoManifestException, ManifestParseError
 import platform_utils
 import progress
-from repo_trace import IsTrace, Trace
+from repo_trace import Trace
 
 from git_refs import GitRefs, HEAD, R_HEADS, R_TAGS, R_PUB, R_M, R_WORKTREE_M
 
 
+class SyncNetworkHalfResult(NamedTuple):
+  """Sync_NetworkHalf return value."""
+  # True if successful.
+  success: bool
+  # Did we query the remote? False when optimized_fetch is True and we have the
+  # commit already present.
+  remote_fetched: bool
+
 # Maximum sleep time allowed during retries.
 MAXIMUM_RETRY_SLEEP_SEC = 3600.0
 # +-10% random jitter is added to each Fetches retry sleep duration.
 RETRY_JITTER_PERCENT = 0.1
 
-# Whether to use alternates.
+# Whether to use alternates.  Switching back and forth is *NOT* supported.
 # TODO(vapier): Remove knob once behavior is verified.
 _ALTERNATES = os.environ.get('REPO_USE_ALTERNATES') == '1'
 
@@ -1133,7 +1142,7 @@ class Project(object):
     if archive and not isinstance(self, MetaProject):
       if self.remote.url.startswith(('http://', 'https://')):
         _error("%s: Cannot fetch archives from http/https remotes.", self.name)
-        return False
+        return SyncNetworkHalfResult(False, False)
 
       name = self.relpath.replace('\\', '/')
       name = name.replace('/', '_')
@@ -1144,19 +1153,19 @@ class Project(object):
         self._FetchArchive(tarpath, cwd=topdir)
       except GitError as e:
         _error('%s', e)
-        return False
+        return SyncNetworkHalfResult(False, False)
 
       # From now on, we only need absolute tarpath
       tarpath = os.path.join(topdir, tarpath)
 
       if not self._ExtractArchive(tarpath, path=topdir):
-        return False
+        return SyncNetworkHalfResult(False, True)
       try:
         platform_utils.remove(tarpath)
       except OSError as e:
         _warn("Cannot remove archive %s: %s", tarpath, str(e))
       self._CopyAndLinkFiles()
-      return True
+      return SyncNetworkHalfResult(True, True)
 
     # If the shared object dir already exists, don't try to rebootstrap with a
     # clone bundle download.  We should have the majority of objects already.
@@ -1220,9 +1229,11 @@ class Project(object):
       depth = self.manifest.manifestProject.depth
 
     # See if we can skip the network fetch entirely.
+    remote_fetched = False
     if not (optimized_fetch and
             (ID_RE.match(self.revisionExpr) and
              self._CheckForImmutableRevision())):
+      remote_fetched = True
       if not self._RemoteFetch(
               initial=is_new,
               quiet=quiet, verbose=verbose, output_redir=output_redir,
@@ -1231,7 +1242,7 @@ class Project(object):
               submodules=submodules, force_sync=force_sync,
               ssh_proxy=ssh_proxy,
               clone_filter=clone_filter, retry_fetches=retry_fetches):
-        return False
+        return SyncNetworkHalfResult(False, remote_fetched)
 
     mp = self.manifest.manifestProject
     dissociate = mp.dissociate
@@ -1244,7 +1255,7 @@ class Project(object):
         if p.stdout and output_redir:
           output_redir.write(p.stdout)
         if p.Wait() != 0:
-          return False
+          return SyncNetworkHalfResult(False, remote_fetched)
         platform_utils.remove(alternates_file)
 
     if self.worktree:
@@ -1253,7 +1264,7 @@ class Project(object):
       self._InitMirrorHead()
       platform_utils.remove(os.path.join(self.gitdir, 'FETCH_HEAD'),
                             missing_ok=True)
-    return True
+    return SyncNetworkHalfResult(True, remote_fetched)
 
   def PostRepoUpgrade(self):
     self._InitHooks()
@@ -1451,6 +1462,8 @@ class Project(object):
         cnt_mine += 1
 
     if not upstream_gain and cnt_mine == len(local_changes):
+      # The copy/linkfile config may have changed.
+      self._CopyAndLinkFiles()
       return
 
     if self.IsDirty(consider_untracked=False):
@@ -2403,16 +2416,16 @@ class Project(object):
         srcUrl = 'http' + srcUrl[len('persistent-http'):]
       cmd += [srcUrl]
 
-      if IsTrace():
-        Trace('%s', ' '.join(cmd))
-      if verbose:
-        print('%s: Downloading bundle: %s' % (self.name, srcUrl))
-      stdout = None if verbose else subprocess.PIPE
-      stderr = None if verbose else subprocess.STDOUT
-      try:
-        proc = subprocess.Popen(cmd, stdout=stdout, stderr=stderr)
-      except OSError:
-        return False
+      proc = None
+      with Trace('Fetching bundle: %s', ' '.join(cmd)):
+        if verbose:
+          print('%s: Downloading bundle: %s' % (self.name, srcUrl))
+        stdout = None if verbose else subprocess.PIPE
+        stderr = None if verbose else subprocess.STDOUT
+        try:
+          proc = subprocess.Popen(cmd, stdout=stdout, stderr=stderr)
+        except OSError:
+          return False
 
       (output, _) = proc.communicate()
       curlret = proc.returncode
@@ -2794,35 +2807,6 @@ class Project(object):
         else:
           raise
 
-  def _InitialCheckoutStart(self):
-    """Called when checking out a project for the first time.
-
-    This will use temporary non-visible paths so we can be safely interrupted
-    without leaving incomplete state behind.
-    """
-    paths = [f'{x}.tmp' for x in (self.relpath, self.worktree, self.gitdir, self.objdir)]
-    for p in paths:
-      platform_utils.rmtree(p, ignore_errors=True)
-    self.UpdatePaths(*paths)
-
-  def _InitialCheckoutFinalizeNetworkHalf(self):
-    """Finalize the object dirs after network syncing works."""
-    # Once the network half finishes, we can move the objects into the right
-    # place by removing the ".tmp" suffix on the dirs.
-    platform_utils.rmtree(self.gitdir[:-4], ignore_errors=True)
-    os.rename(self.gitdir, self.gitdir[:-4])
-    self.UpdatePaths(self.relpath, self.worktree, self.gitdir[:-4], self.objdir[:-4])
-
-  def _InitialCheckoutFinalizeLocalHalf(self):
-    """Finalize the initial checkout and make it available."""
-    assert self.gitdir == self.objdir
-    # Once the local half finishes, we can move the manifest dir into the right
-    # place by removing the ".tmp" suffix on the dirs.
-    platform_utils.rmtree(self.worktree[:-4], ignore_errors=True)
-    os.rename(self.worktree, self.worktree[:-4])
-    self.UpdatePaths(
-        self.relpath[:-4], self.worktree[:-4], self.gitdir, self.objdir)
-
   def _InitGitWorktree(self):
     """Init the project using git worktrees."""
     self.bare_git.worktree('prune')
@@ -3709,8 +3693,6 @@ class ManifestProject(MetaProject):
               (GitConfig.ForUser().UrlInsteadOf(manifest_url),),
               file=sys.stderr)
 
-      self._InitialCheckoutStart()
-
       # The manifest project object doesn't keep track of the path on the
       # server where this git is located, so let's save that here.
       mirrored_manifest_git = None
@@ -3867,17 +3849,19 @@ class ManifestProject(MetaProject):
           is_new=is_new, quiet=not verbose, verbose=verbose,
           clone_bundle=clone_bundle, current_branch_only=current_branch_only,
           tags=tags, submodules=submodules, clone_filter=clone_filter,
-          partial_clone_exclude=self.manifest.PartialCloneExclude):
+          partial_clone_exclude=self.manifest.PartialCloneExclude).success:
         r = self.GetRemote()
         print('fatal: cannot obtain manifest %s' % r.url, file=sys.stderr)
+
+        # Better delete the manifest git dir if we created it; otherwise next
+        # time (when user fixes problems) we won't go through the "is_new" logic.
+        if is_new:
+          platform_utils.rmtree(self.gitdir)
         return False
 
       if manifest_branch:
         self.MetaBranchSwitch(submodules=submodules)
 
-      if is_new:
-        self._InitialCheckoutFinalizeNetworkHalf()
-
       syncbuf = SyncBuffer(self.config)
       self.Sync_LocalHalf(syncbuf, submodules=submodules)
       syncbuf.Finish()
@@ -3900,9 +3884,6 @@ class ManifestProject(MetaProject):
       with open(dest, 'wb') as f:
         f.write(manifest_data)
 
-    if is_new:
-      self._InitialCheckoutFinalizeLocalHalf()
-
     try:
       self.manifest.Link(manifest_name)
     except ManifestParseError as e:

release/update-manpages

@@ -59,18 +59,26 @@ def main(argv):
   version = RepoSourceVersion()
   cmdlist = [['help2man', '-N', '-n', f'repo {cmd} - manual page for repo {cmd}',
     '-S', f'repo {cmd}', '-m', 'Repo Manual', f'--version-string={version}',
-    '-o', MANDIR.joinpath(f'repo-{cmd}.1.tmp'), TOPDIR.joinpath('repo'),
+    '-o', MANDIR.joinpath(f'repo-{cmd}.1.tmp'), './repo',
     '-h', f'help {cmd}'] for cmd in subcmds.all_commands]
   cmdlist.append(['help2man', '-N', '-n', 'repository management tool built on top of git',
     '-S', 'repo', '-m', 'Repo Manual', f'--version-string={version}',
-    '-o', MANDIR.joinpath('repo.1.tmp'), TOPDIR.joinpath('repo'),
+    '-o', MANDIR.joinpath('repo.1.tmp'), './repo',
     '-h', '--help-all'])
 
   with tempfile.TemporaryDirectory() as tempdir:
-    repo_dir = Path(tempdir) / '.repo'
+    tempdir = Path(tempdir)
+    repo_dir = tempdir / '.repo'
     repo_dir.mkdir()
     (repo_dir / 'repo').symlink_to(TOPDIR)
 
+    # Create a repo wrapper using the active Python executable.  We can't pass
+    # this directly to help2man as it's too simple, so insert it via shebang.
+    data = (TOPDIR / 'repo').read_text(encoding='utf-8')
+    tempbin = tempdir / 'repo'
+    tempbin.write_text(f'#!{sys.executable}\n' + data, encoding='utf-8')
+    tempbin.chmod(0o755)
+
     # Run all cmd in parallel, and wait for them to finish.
     with multiprocessing.Pool() as pool:
       pool.map(partial(worker, cwd=tempdir, check=True), cmdlist)

repo

@@ -316,9 +316,10 @@ def InitParser(parser, gitc_init=False):
                    help='download the manifest as a static file '
                         'rather then create a git checkout of '
                         'the manifest repo')
-  group.add_option('--manifest-depth', type='int', default=1, metavar='DEPTH',
+  group.add_option('--manifest-depth', type='int', default=0, metavar='DEPTH',
                    help='create a shallow clone of the manifest repo with '
-                        'given depth; see git clone (default: %default)')
+                        'given depth (0 for full clone); see git clone '
+                        '(default: %default)')
 
   # Options that only affect manifest project, and not any of the projects
   # specified in the manifest itself.

repo_trace.py

@@ -15,26 +15,124 @@
 """Logic for tracing repo interactions.
 
 Activated via `repo --trace ...` or `REPO_TRACE=1 repo ...`.
+
+Temporary: Tracing is always on. Set `REPO_TRACE=0` to turn off.
+To also include trace outputs in stderr do `repo --trace_to_stderr ...`
 """
 
 import sys
 import os
+import time
+from contextlib import ContextDecorator
+
+import platform_utils
 
 # Env var to implicitly turn on tracing.
 REPO_TRACE = 'REPO_TRACE'
 
-_TRACE = os.environ.get(REPO_TRACE) == '1'
+# Temporarily set tracing to always on unless user expicitly sets to 0.
+_TRACE = os.environ.get(REPO_TRACE) != '0'
+_TRACE_TO_STDERR = False
+_TRACE_FILE = None
+_TRACE_FILE_NAME = 'TRACE_FILE'
+_MAX_SIZE = 70  # in mb
+_NEW_COMMAND_SEP = '+++++++++++++++NEW COMMAND+++++++++++++++++++'
+
+
+def IsTraceToStderr():
+  return _TRACE_TO_STDERR
 
 
 def IsTrace():
   return _TRACE
 
 
+def SetTraceToStderr():
+  global _TRACE_TO_STDERR
+  _TRACE_TO_STDERR = True
+
+
 def SetTrace():
   global _TRACE
   _TRACE = True
 
 
-def Trace(fmt, *args):
-  if IsTrace():
-    print(fmt % args, file=sys.stderr)
+def _SetTraceFile():
+  global _TRACE_FILE
+  _TRACE_FILE = _GetTraceFile()
+
+
+class Trace(ContextDecorator):
+
+    def _time(self):
+      """Generate nanoseconds of time in a py3.6 safe way"""
+      return int(time.time()*1e+9)
+
+    def __init__(self, fmt, *args, first_trace=False):
+      if not IsTrace():
+        return
+      self._trace_msg = fmt % args
+
+      if not _TRACE_FILE:
+        _SetTraceFile()
+
+      if first_trace:
+        _ClearOldTraces()
+        self._trace_msg = '%s %s' % (_NEW_COMMAND_SEP, self._trace_msg)
+
+
+    def __enter__(self):
+      if not IsTrace():
+        return self
+
+      print_msg = f'PID: {os.getpid()} START: {self._time()} :' + self._trace_msg + '\n'
+
+      with open(_TRACE_FILE, 'a') as f:
+        print(print_msg, file=f)
+
+      if _TRACE_TO_STDERR:
+        print(print_msg, file=sys.stderr)
+
+      return self
+
+    def __exit__(self, *exc):
+      if not IsTrace():
+        return False
+
+      print_msg = f'PID: {os.getpid()} END: {self._time()} :' + self._trace_msg + '\n'
+
+      with open(_TRACE_FILE, 'a') as f:
+        print(print_msg, file=f)
+
+      if _TRACE_TO_STDERR:
+        print(print_msg, file=sys.stderr)
+
+      return False
+
+
+def _GetTraceFile():
+  """Get the trace file or create one."""
+  # TODO: refactor to pass repodir to Trace.
+  repo_dir = os.path.dirname(os.path.dirname(__file__))
+  trace_file = os.path.join(repo_dir, _TRACE_FILE_NAME)
+  print('Trace outputs in %s' % trace_file, file=sys.stderr)
+  return trace_file
+
+def _ClearOldTraces():
+  """Clear the oldest commands if trace file is too big.
+
+  Note: If the trace file contains output from two `repo`
+        commands that were running at the same time, this
+        will not work precisely.
+  """
+  if os.path.isfile(_TRACE_FILE):
+    while os.path.getsize(_TRACE_FILE)/(1024*1024) > _MAX_SIZE:
+      temp_file = _TRACE_FILE + '.tmp'
+      with open(_TRACE_FILE, 'r', errors='ignore') as fin:
+        with open(temp_file, 'w') as tf:
+          trace_lines = fin.readlines()
+          for i , l in enumerate(trace_lines):
+            if 'END:' in l and _NEW_COMMAND_SEP in l:
+              tf.writelines(trace_lines[i+1:])
+              break
+      platform_utils.rename(temp_file, _TRACE_FILE)

run_tests

@@ -20,6 +20,7 @@ import os
 import shutil
 import subprocess
 import sys
+import repo_trace
 
 
 def find_pytest():

ssh.py

@@ -182,28 +182,29 @@ class ProxyManager:
     # be important because we can't tell that that 'git@myhost.com' is the same
     # as 'myhost.com' where "User git" is setup in the user's ~/.ssh/config file.
     check_command = command_base + ['-O', 'check']
-    try:
-      Trace(': %s', ' '.join(check_command))
-      check_process = subprocess.Popen(check_command,
-                                       stdout=subprocess.PIPE,
-                                       stderr=subprocess.PIPE)
-      check_process.communicate()  # read output, but ignore it...
-      isnt_running = check_process.wait()
+    with Trace('Call to ssh (check call): %s', ' '.join(check_command)):
+      try:
+        check_process = subprocess.Popen(check_command,
+                                        stdout=subprocess.PIPE,
+                                        stderr=subprocess.PIPE)
+        check_process.communicate()  # read output, but ignore it...
+        isnt_running = check_process.wait()
 
-      if not isnt_running:
-        # Our double-check found that the master _was_ infact running.  Add to
-        # the list of keys.
-        self._master_keys[key] = True
-        return True
-    except Exception:
-      # Ignore excpetions.  We we will fall back to the normal command and print
-      # to the log there.
-      pass
+        if not isnt_running:
+          # Our double-check found that the master _was_ infact running.  Add to
+          # the list of keys.
+          self._master_keys[key] = True
+          return True
+      except Exception:
+        # Ignore excpetions.  We we will fall back to the normal command and
+        # print to the log there.
+        pass
 
     command = command_base[:1] + ['-M', '-N'] + command_base[1:]
+    p = None
     try:
-      Trace(': %s', ' '.join(command))
-      p = subprocess.Popen(command)
+      with Trace('Call to ssh: %s', ' '.join(command)):
+        p = subprocess.Popen(command)
     except Exception as e:
       self._master_broken.value = True
       print('\nwarn: cannot enable ssh control master for %s:%s\n%s'

subcmds/diffmanifests.py

@@ -118,6 +118,16 @@ synced and their revisions won't be found.
         self.printRevision(project.revisionExpr)
         self.out.nl()
 
+    if diff['missing']:
+      self.out.nl()
+      self.printText('missing projects : \n')
+      self.out.nl()
+      for project in diff['missing']:
+        self.printProject('\t%s' % (project.relpath))
+        self.printText(' at revision ')
+        self.printRevision(project.revisionExpr)
+        self.out.nl()
+
     if diff['changed']:
       self.out.nl()
       self.printText('changed projects : \n')

subcmds/gitc_init.py

@@ -68,7 +68,8 @@ use for this GITC client.
         sys.exit(1)
       manifest_file = opt.manifest_file
 
-    manifest = GitcManifest(self.repodir, gitc_client)
+    manifest = GitcManifest(self.repodir, os.path.join(self.client_dir,
+                                                       '.manifest'))
     manifest.Override(manifest_file)
     gitc_utils.generate_gitc_manifest(None, manifest)
     print('Please run `cd %s` to view your GITC client.' %

subcmds/selfupdate.py

@@ -51,7 +51,7 @@ need to be performed by an end-user.
       _PostRepoUpgrade(self.manifest)
 
     else:
-      if not rp.Sync_NetworkHalf():
+      if not rp.Sync_NetworkHalf().success:
         print("error: can't update repo", file=sys.stderr)
         sys.exit(1)
 

subcmds/sync.py

@@ -21,10 +21,12 @@ import multiprocessing
 import netrc
 from optparse import SUPPRESS_HELP
 import os
+import shutil
 import socket
 import sys
 import tempfile
 import time
+from typing import NamedTuple, List, Set
 import urllib.error
 import urllib.parse
 import urllib.request
@@ -58,11 +60,71 @@ from error import RepoChangedException, GitError, ManifestParseError
 import platform_utils
 from project import SyncBuffer
 from progress import Progress
+from repo_trace import Trace
 import ssh
 from wrapper import Wrapper
 from manifest_xml import GitcManifest
 
 _ONE_DAY_S = 24 * 60 * 60
+# Env var to implicitly turn off object backups.
+REPO_BACKUP_OBJECTS = 'REPO_BACKUP_OBJECTS'
+_BACKUP_OBJECTS = os.environ.get(REPO_BACKUP_OBJECTS) != '0'
+
+# Env var to implicitly turn auto-gc back on.
+_REPO_AUTO_GC = 'REPO_AUTO_GC'
+_AUTO_GC = os.environ.get(_REPO_AUTO_GC) == '1'
+
+
+class _FetchOneResult(NamedTuple):
+  """_FetchOne return value.
+
+  Attributes:
+    success (bool): True if successful.
+    project (Project): The fetched project.
+    start (float): The starting time.time().
+    finish (float): The ending time.time().
+    remote_fetched (bool): True if the remote was actually queried.
+  """
+  success: bool
+  project: Project
+  start: float
+  finish: float
+  remote_fetched: bool
+
+
+class _FetchResult(NamedTuple):
+  """_Fetch return value.
+
+  Attributes:
+    success (bool): True if successful.
+    projects (Set[str]): The names of the git directories of fetched projects.
+  """
+  success: bool
+  projects: Set[str]
+
+
+class _FetchMainResult(NamedTuple):
+  """_FetchMain return value.
+
+  Attributes:
+    all_projects (List[Project]): The fetched projects.
+  """
+  all_projects: List[Project]
+
+
+class _CheckoutOneResult(NamedTuple):
+  """_CheckoutOne return value.
+
+  Attributes:
+    success (bool): True if successful.
+    project (Project): The project.
+    start (float): The starting time.time().
+    finish (float): The ending time.time().
+  """
+  success: bool
+  project: Project
+  start: float
+  finish: float
 
 
 class Sync(Command, MirrorSafeCommand):
@@ -141,6 +203,9 @@ exist locally.
 The --prune option can be used to remove any refs that no longer
 exist on the remote.
 
+The --auto-gc option can be used to trigger garbage collection on all
+projects. By default, repo does not run garbage collection.
+
 # SSH Connections
 
 If at least one project remote URL uses an SSH connection (ssh://,
@@ -250,6 +315,10 @@ later is required to fix a server side protocol bug.
                  help='delete refs that no longer exist on the remote (default)')
     p.add_option('--no-prune', dest='prune', action='store_false',
                  help='do not delete refs that no longer exist on the remote')
+    p.add_option('--auto-gc', action='store_true', default=None,
+                 help='run garbage collection on all synced projects')
+    p.add_option('--no-auto-gc', dest='auto_gc', action='store_false',
+                 help='do not run garbage collection on any projects (default)')
     if show_smart:
       p.add_option('-s', '--smart-sync',
                    dest='smart_sync', action='store_true',
@@ -406,7 +475,7 @@ later is required to fix a server side protocol bug.
     success = False
     buf = io.StringIO()
     try:
-      success = project.Sync_NetworkHalf(
+      sync_result = project.Sync_NetworkHalf(
           quiet=opt.quiet,
           verbose=opt.verbose,
           output_redir=buf,
@@ -420,6 +489,7 @@ later is required to fix a server side protocol bug.
           ssh_proxy=self.ssh_proxy,
           clone_filter=project.manifest.CloneFilter,
           partial_clone_exclude=project.manifest.PartialCloneExclude)
+      success = sync_result.success
 
       output = buf.getvalue()
       if (opt.verbose or not success) and output:
@@ -437,7 +507,8 @@ later is required to fix a server side protocol bug.
       raise
 
     finish = time.time()
-    return (success, project, start, finish)
+    return _FetchOneResult(success, project, start, finish,
+                           sync_result.remote_fetched)
 
   @classmethod
   def _FetchInitChild(cls, ssh_proxy):
@@ -448,6 +519,7 @@ later is required to fix a server side protocol bug.
 
     jobs = opt.jobs_network
     fetched = set()
+    remote_fetched = set()
     pm = Progress('Fetching', len(projects), delay=False, quiet=opt.quiet)
 
     objdir_project_map = dict()
@@ -458,10 +530,16 @@ later is required to fix a server side protocol bug.
     def _ProcessResults(results_sets):
       ret = True
       for results in results_sets:
-        for (success, project, start, finish) in results:
+        for result in results:
+          success = result.success
+          project = result.project
+          start = result.start
+          finish = result.finish
           self._fetch_times.Set(project, finish - start)
           self.event_log.AddSync(project, event_log.TASK_SYNC_NETWORK,
                                  start, finish, success)
+          if result.remote_fetched:
+            remote_fetched.add(project)
           # Check for any errors before running any more tasks.
           # ...we'll let existing jobs finish, though.
           if not success:
@@ -519,7 +597,7 @@ later is required to fix a server side protocol bug.
     if not self.outer_client.manifest.IsArchive:
       self._GCProjects(projects, opt, err_event)
 
-    return (ret, fetched)
+    return _FetchResult(ret, fetched)
 
   def _FetchMain(self, opt, args, all_projects, err_event,
                  ssh_proxy, manifest):
@@ -545,7 +623,9 @@ later is required to fix a server side protocol bug.
     to_fetch.extend(all_projects)
     to_fetch.sort(key=self._fetch_times.Get, reverse=True)
 
-    success, fetched = self._Fetch(to_fetch, opt, err_event, ssh_proxy)
+    result = self._Fetch(to_fetch, opt, err_event, ssh_proxy)
+    success = result.success
+    fetched = result.projects
     if not success:
       err_event.set()
 
@@ -555,7 +635,7 @@ later is required to fix a server side protocol bug.
       if err_event.is_set():
         print('\nerror: Exited sync due to fetch errors.\n', file=sys.stderr)
         sys.exit(1)
-      return
+      return _FetchMainResult([])
 
     # Iteratively fetch missing and/or nested unregistered submodules
     previously_missing_set = set()
@@ -578,12 +658,14 @@ later is required to fix a server side protocol bug.
       if previously_missing_set == missing_set:
         break
       previously_missing_set = missing_set
-      success, new_fetched = self._Fetch(missing, opt, err_event, ssh_proxy)
+      result = self._Fetch(missing, opt, err_event, ssh_proxy)
+      success = result.success
+      new_fetched = result.projects
       if not success:
         err_event.set()
       fetched.update(new_fetched)
 
-    return all_projects
+    return _FetchMainResult(all_projects)
 
   def _CheckoutOne(self, detach_head, force_sync, project):
     """Checkout work tree for one project
@@ -615,7 +697,7 @@ later is required to fix a server side protocol bug.
     if not success:
       print('error: Cannot checkout %s' % (project.name), file=sys.stderr)
     finish = time.time()
-    return (success, project, start, finish)
+    return _CheckoutOneResult(success, project, start, finish)
 
   def _Checkout(self, all_projects, opt, err_results):
     """Checkout projects listed in all_projects
@@ -630,7 +712,11 @@ later is required to fix a server side protocol bug.
 
     def _ProcessResults(pool, pm, results):
       ret = True
-      for (success, project, start, finish) in results:
+      for result in results:
+        success = result.success
+        project = result.project
+        start = result.start
+        finish = result.finish
         self.event_log.AddSync(project, event_log.TASK_SYNC_LOCAL,
                                start, finish, success)
         # Check for any errors before running any more tasks.
@@ -652,33 +738,121 @@ later is required to fix a server side protocol bug.
         callback=_ProcessResults,
         output=Progress('Checking out', len(all_projects), quiet=opt.quiet)) and not err_results
 
+  def _backup_cruft(self, bare_git):
+    """Save a copy of any cruft from `git gc`."""
+    # Find any cruft packs in the current gitdir, and save them.
+    # b/221065125 (repo sync complains that objects are missing).  This does
+    # not prevent that state, but makes it so that the missing objects are
+    # available.
+    objdir = bare_git._project.objdir
+    pack_dir = os.path.join(objdir, 'pack')
+    bak_dir = os.path.join(objdir, '.repo', 'pack.bak')
+    if not _BACKUP_OBJECTS or not platform_utils.isdir(pack_dir):
+      return
+    files = set(platform_utils.listdir(pack_dir))
+    to_backup = []
+    for f in files:
+      base, ext = os.path.splitext(f)
+      if base + '.mtimes' in files:
+        to_backup.append(f)
+    if to_backup:
+      os.makedirs(bak_dir, exist_ok=True)
+    for fname in to_backup:
+      bak_fname = os.path.join(bak_dir, fname)
+      if not os.path.exists(bak_fname):
+        with Trace('%s saved %s', bare_git._project.name, fname):
+          # Use a tmp file so that we are sure of a complete copy.
+          shutil.copy(os.path.join(pack_dir, fname), bak_fname + '.tmp')
+          shutil.move(bak_fname + '.tmp', bak_fname)
+
+  @staticmethod
+  def _GetPreciousObjectsState(project: Project, opt):
+    """Get the preciousObjects state for the project.
+
+    Args:
+      project (Project): the project to examine, and possibly correct.
+      opt (optparse.Values): options given to sync.
+
+    Returns:
+      Expected state of extensions.preciousObjects:
+        False: Should be disabled. (not present)
+        True: Should be enabled.
+    """
+    if project.use_git_worktrees:
+      return False
+    projects = project.manifest.GetProjectsWithName(project.name,
+                                                    all_manifests=True)
+    if len(projects) == 1:
+      return False
+    relpath = project.RelPath(local=opt.this_manifest_only)
+    if len(projects) > 1:
+      # Objects are potentially shared with another project.
+      # See the logic in Project.Sync_NetworkHalf regarding UseAlternates.
+      # - When False, shared projects share (via symlink)
+      #   .repo/project-objects/{PROJECT_NAME}.git as the one-and-only objects
+      #   directory.  All objects are precious, since there is no project with a
+      #   complete set of refs.
+      # - When True, shared projects share (via info/alternates)
+      #   .repo/project-objects/{PROJECT_NAME}.git as an alternate object store,
+      #   which is written only on the first clone of the project, and is not
+      #   written subsequently.  (When Sync_NetworkHalf sees that it exists, it
+      #   makes sure that the alternates file points there, and uses a
+      #   project-local .git/objects directory for all syncs going forward.
+      # We do not support switching between the options.  The environment
+      # variable is present for testing and migration only.
+      return not project.UseAlternates
+    print(f'\r{relpath}: project not found in manifest.', file=sys.stderr)
+    return False
+
+  def _RepairPreciousObjectsState(self, project: Project, opt):
+    """Correct the preciousObjects state for the project.
+
+    Args:
+      project (Project): the project to examine, and possibly correct.
+      opt (optparse.Values): options given to sync.
+    """
+    expected = self._GetPreciousObjectsState(project, opt)
+    actual = project.config.GetBoolean('extensions.preciousObjects') or False
+    relpath = project.RelPath(local = opt.this_manifest_only)
+
+    if (expected != actual and
+        not project.config.GetBoolean('repo.preservePreciousObjects')):
+      # If this is unexpected, log it and repair.
+      Trace(f'{relpath} expected preciousObjects={expected}, got {actual}')
+      if expected:
+        if not opt.quiet:
+          print('\r%s: Shared project %s found, disabling pruning.' %
+                (relpath, project.name))
+        if git_require((2, 7, 0)):
+          project.EnableRepositoryExtension('preciousObjects')
+        else:
+          # This isn't perfect, but it's the best we can do with old git.
+          print('\r%s: WARNING: shared projects are unreliable when using '
+                'old versions of git; please upgrade to git-2.7.0+.'
+                % (relpath,),
+                file=sys.stderr)
+          project.config.SetString('gc.pruneExpire', 'never')
+      else:
+        if not opt.quiet:
+          print(f'\r{relpath}: not shared, disabling pruning.')
+        project.config.SetString('extensions.preciousObjects', None)
+        project.config.SetString('gc.pruneExpire', None)
+
   def _GCProjects(self, projects, opt, err_event):
-    pm = Progress('Garbage collecting', len(projects), delay=False, quiet=opt.quiet)
+    """Perform garbage collection.
+
+    If We are skipping garbage collection (opt.auto_gc not set), we still want
+    to potentially mark objects precious, so that `git gc` does not discard
+    shared objects.
+    """
+    pm = Progress(f'{"" if opt.auto_gc else "NOT "}Garbage collecting',
+                  len(projects), delay=False, quiet=opt.quiet)
     pm.update(inc=0, msg='prescan')
 
     tidy_dirs = {}
     for project in projects:
-      # Make sure pruning never kicks in with shared projects that do not use
-      # alternates to avoid corruption.
-      if (not project.use_git_worktrees and
-              len(project.manifest.GetProjectsWithName(project.name, all_manifests=True)) > 1):
-        if project.UseAlternates:
-          # Undo logic set by previous versions of repo.
-          project.config.SetString('extensions.preciousObjects', None)
-          project.config.SetString('gc.pruneExpire', None)
-        else:
-          if not opt.quiet:
-            print('\r%s: Shared project %s found, disabling pruning.' %
-                  (project.relpath, project.name))
-          if git_require((2, 7, 0)):
-            project.EnableRepositoryExtension('preciousObjects')
-          else:
-            # This isn't perfect, but it's the best we can do with old git.
-            print('\r%s: WARNING: shared projects are unreliable when using old '
-                  'versions of git; please upgrade to git-2.7.0+.'
-                  % (project.relpath,),
-                  file=sys.stderr)
-            project.config.SetString('gc.pruneExpire', 'never')
+      self._RepairPreciousObjectsState(project, opt)
+
       project.config.SetString('gc.autoDetach', 'false')
       # Only call git gc once per objdir, but call pack-refs for the remainder.
       if project.objdir not in tidy_dirs:
@@ -692,15 +866,28 @@ later is required to fix a server side protocol bug.
             project.bare_git,
         )
 
+    if not opt.auto_gc:
+      pm.end()
+      return
+
     jobs = opt.jobs
 
+    gc_args = ['--auto']
+    backup_cruft = False
+    if git_require((2, 37, 0)):
+      gc_args.append('--cruft')
+      backup_cruft = True
+    pack_refs_args = ()
     if jobs < 2:
       for (run_gc, bare_git) in tidy_dirs.values():
         pm.update(msg=bare_git._project.name)
+
         if run_gc:
-          bare_git.gc('--auto')
+          bare_git.gc(*gc_args)
         else:
-          bare_git.pack_refs()
+          bare_git.pack_refs(*pack_refs_args)
+        if backup_cruft:
+          self._backup_cruft(bare_git)
       pm.end()
       return
 
@@ -715,15 +902,17 @@ later is required to fix a server side protocol bug.
       try:
         try:
           if run_gc:
-            bare_git.gc('--auto', config=config)
+            bare_git.gc(*gc_args, config=config)
           else:
-            bare_git.pack_refs(config=config)
+            bare_git.pack_refs(*pack_refs_args, config=config)
         except GitError:
           err_event.set()
         except Exception:
           err_event.set()
           raise
       finally:
+        if backup_cruft:
+          self._backup_cruft(bare_git)
         pm.finish(bare_git._project.name)
         sem.release()
 
@@ -1033,6 +1222,11 @@ later is required to fix a server side protocol bug.
     if opt.prune is None:
       opt.prune = True
 
+    if opt.auto_gc is None and _AUTO_GC:
+      print(f"Will run `git gc --auto` because {_REPO_AUTO_GC} is set.",
+            file=sys.stderr)
+      opt.auto_gc = True
+
   def Execute(self, opt, args):
     manifest = self.outer_manifest
     if not opt.outer_manifest:
@@ -1160,6 +1354,7 @@ later is required to fix a server side protocol bug.
 
     err_network_sync = False
     err_update_projects = False
+    err_update_linkfiles = False
 
     self._fetch_times = _FetchTimes(manifest)
     if not opt.local_only:
@@ -1167,8 +1362,9 @@ later is required to fix a server side protocol bug.
         with ssh.ProxyManager(manager) as ssh_proxy:
           # Initialize the socket dir once in the parent.
           ssh_proxy.sock()
-          all_projects = self._FetchMain(opt, args, all_projects, err_event,
-                                         ssh_proxy, manifest)
+          result = self._FetchMain(opt, args, all_projects, err_event,
+                                   ssh_proxy, manifest)
+          all_projects = result.all_projects
 
       if opt.network_only:
         return

tests/test_git_config.py

@@ -19,6 +19,7 @@ import tempfile
 import unittest
 
 import git_config
+import repo_trace
 
 
 def fixture(*paths):
@@ -33,9 +34,16 @@ class GitConfigReadOnlyTests(unittest.TestCase):
   def setUp(self):
     """Create a GitConfig object using the test.gitconfig fixture.
     """
+
+    self.tempdirobj = tempfile.TemporaryDirectory(prefix='repo_tests')
+    repo_trace._TRACE_FILE = os.path.join(self.tempdirobj.name, 'TRACE_FILE_from_test')
+
     config_fixture = fixture('test.gitconfig')
     self.config = git_config.GitConfig(config_fixture)
 
+  def tearDown(self):
+    self.tempdirobj.cleanup()
+
   def test_GetString_with_empty_config_values(self):
     """
     Test config entries with no value.
@@ -109,9 +117,15 @@ class GitConfigReadWriteTests(unittest.TestCase):
   """Read/write tests of the GitConfig class."""
 
   def setUp(self):
+    self.tempdirobj = tempfile.TemporaryDirectory(prefix='repo_tests')
+    repo_trace._TRACE_FILE = os.path.join(self.tempdirobj.name, 'TRACE_FILE_from_test')
+
     self.tmpfile = tempfile.NamedTemporaryFile()
     self.config = self.get_config()
 
+  def tearDown(self):
+    self.tempdirobj.cleanup()
+
   def get_config(self):
     """Get a new GitConfig instance."""
     return git_config.GitConfig(self.tmpfile.name)

tests/test_git_superproject.py

@@ -24,6 +24,7 @@ from unittest import mock
 import git_superproject
 import git_trace2_event_log
 import manifest_xml
+import repo_trace
 from test_manifest_xml import sort_attributes
 
 
@@ -39,6 +40,7 @@ class SuperprojectTestCase(unittest.TestCase):
     """Set up superproject every time."""
     self.tempdirobj = tempfile.TemporaryDirectory(prefix='repo_tests')
     self.tempdir = self.tempdirobj.name
+    repo_trace._TRACE_FILE = os.path.join(self.tempdir, 'TRACE_FILE_from_test')
     self.repodir = os.path.join(self.tempdir, '.repo')
     self.manifest_file = os.path.join(
         self.repodir, manifest_xml.MANIFEST_FILE_NAME)

tests/test_manifest_xml.py

@@ -23,6 +23,7 @@ import xml.dom.minidom
 
 import error
 import manifest_xml
+import repo_trace
 
 
 # Invalid paths that we don't want in the filesystem.
@@ -93,6 +94,7 @@ class ManifestParseTestCase(unittest.TestCase):
   def setUp(self):
     self.tempdirobj = tempfile.TemporaryDirectory(prefix='repo_tests')
     self.tempdir = self.tempdirobj.name
+    repo_trace._TRACE_FILE = os.path.join(self.tempdir, 'TRACE_FILE_from_test')
     self.repodir = os.path.join(self.tempdir, '.repo')
     self.manifest_dir = os.path.join(self.repodir, 'manifests')
     self.manifest_file = os.path.join(
@@ -262,10 +264,10 @@ class XmlManifestTests(ManifestParseTestCase):
         '<project name="r" groups="keep"/>'
         '</manifest>')
     self.assertEqual(
-        manifest.ToXml(omit_local=True).toxml(),
+        sort_attributes(manifest.ToXml(omit_local=True).toxml()),
         '<?xml version="1.0" ?><manifest>'
-        '<remote name="a" fetch=".."/><default remote="a" revision="r"/>'
-        '<project name="q"/><project name="r" groups="keep"/></manifest>')
+        '<remote fetch=".." name="a"/><default remote="a" revision="r"/>'
+        '<project name="q"/><project groups="keep" name="r"/></manifest>')
 
   def test_toxml_with_local(self):
     """Does include local_manifests projects when omit_local=False."""
@@ -277,11 +279,11 @@ class XmlManifestTests(ManifestParseTestCase):
         '<project name="r" groups="keep"/>'
         '</manifest>')
     self.assertEqual(
-        manifest.ToXml(omit_local=False).toxml(),
+        sort_attributes(manifest.ToXml(omit_local=False).toxml()),
         '<?xml version="1.0" ?><manifest>'
-        '<remote name="a" fetch=".."/><default remote="a" revision="r"/>'
-        '<project name="p" groups="local::me"/>'
-        '<project name="q"/><project name="r" groups="keep"/></manifest>')
+        '<remote fetch=".." name="a"/><default remote="a" revision="r"/>'
+        '<project groups="local::me" name="p"/>'
+        '<project name="q"/><project groups="keep" name="r"/></manifest>')
 
   def test_repo_hooks(self):
     """Check repo-hooks settings."""
@@ -874,3 +876,27 @@ class ExtendProjectElementTests(ManifestParseTestCase):
     else:
       self.assertEqual(manifest.projects[0].relpath, 'bar')
       self.assertEqual(manifest.projects[1].relpath, 'y')
+
+  def test_extend_project_dest_branch(self):
+    manifest = self.getXmlManifest("""
+<manifest>
+  <remote name="default-remote" fetch="http://localhost" />
+  <default remote="default-remote" revision="refs/heads/main" dest-branch="foo" />
+  <project name="myproject" />
+  <extend-project name="myproject" dest-branch="bar" />
+</manifest>
+""")
+    self.assertEqual(len(manifest.projects), 1)
+    self.assertEqual(manifest.projects[0].dest_branch, 'bar')
+
+  def test_extend_project_upstream(self):
+    manifest = self.getXmlManifest("""
+<manifest>
+  <remote name="default-remote" fetch="http://localhost" />
+  <default remote="default-remote" revision="refs/heads/main" />
+  <project name="myproject" />
+  <extend-project name="myproject" upstream="bar" />
+</manifest>
+""")
+    self.assertEqual(len(manifest.projects), 1)
+    self.assertEqual(manifest.projects[0].upstream, 'bar')

tests/test_project.py

@@ -26,6 +26,7 @@ import git_command
 import git_config
 import platform_utils
 import project
+import repo_trace
 
 
 @contextlib.contextmanager
@@ -64,6 +65,13 @@ class FakeProject(object):
 class ReviewableBranchTests(unittest.TestCase):
   """Check ReviewableBranch behavior."""
 
+  def setUp(self):
+    self.tempdirobj = tempfile.TemporaryDirectory(prefix='repo_tests')
+    repo_trace._TRACE_FILE = os.path.join(self.tempdirobj.name, 'TRACE_FILE_from_test')
+
+  def tearDown(self):
+    self.tempdirobj.cleanup()
+
   def test_smoke(self):
     """A quick run through everything."""
     with TempGitTree() as tempdir:

tests/test_subcmds_sync.py

@@ -11,9 +11,9 @@
 # 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/sync.py module."""
 
+import unittest
 from unittest import mock
 
 import pytest
@@ -21,17 +21,14 @@ import pytest
 from subcmds import sync
 
 
-@pytest.mark.parametrize(
-  'use_superproject, cli_args, result',
-  [
+@pytest.mark.parametrize('use_superproject, cli_args, result', [
     (True, ['--current-branch'], True),
     (True, ['--no-current-branch'], True),
     (True, [], True),
     (False, ['--current-branch'], True),
     (False, ['--no-current-branch'], False),
     (False, [], None),
-  ]
-)
+])
 def test_get_current_branch_only(use_superproject, cli_args, result):
   """Test Sync._GetCurrentBranchOnly logic.
 
@@ -41,5 +38,49 @@ def test_get_current_branch_only(use_superproject, cli_args, result):
   cmd = sync.Sync()
   opts, _ = cmd.OptionParser.parse_args(cli_args)
 
-  with mock.patch('git_superproject.UseSuperproject', return_value=use_superproject):
+  with mock.patch('git_superproject.UseSuperproject',
+                  return_value=use_superproject):
     assert cmd._GetCurrentBranchOnly(opts, cmd.manifest) == result
+
+
+class GetPreciousObjectsState(unittest.TestCase):
+  """Tests for _GetPreciousObjectsState."""
+
+  def setUp(self):
+    """Common setup."""
+    self.cmd = sync.Sync()
+    self.project = p = mock.MagicMock(use_git_worktrees=False,
+                                      UseAlternates=False)
+    p.manifest.GetProjectsWithName.return_value = [p]
+
+    self.opt = mock.Mock(spec_set=['this_manifest_only'])
+    self.opt.this_manifest_only = False
+
+  def test_worktrees(self):
+    """False for worktrees."""
+    self.project.use_git_worktrees = True
+    self.assertFalse(self.cmd._GetPreciousObjectsState(self.project, self.opt))
+
+  def test_not_shared(self):
+    """Singleton project."""
+    self.assertFalse(self.cmd._GetPreciousObjectsState(self.project, self.opt))
+
+  def test_shared(self):
+    """Shared project."""
+    self.project.manifest.GetProjectsWithName.return_value = [
+        self.project, self.project
+    ]
+    self.assertTrue(self.cmd._GetPreciousObjectsState(self.project, self.opt))
+
+  def test_shared_with_alternates(self):
+    """Shared project, with alternates."""
+    self.project.manifest.GetProjectsWithName.return_value = [
+        self.project, self.project
+    ]
+    self.project.UseAlternates = True
+    self.assertFalse(self.cmd._GetPreciousObjectsState(self.project, self.opt))
+
+  def test_not_found(self):
+    """Project not found in manifest."""
+    self.project.manifest.GetProjectsWithName.return_value = []
+    self.assertFalse(self.cmd._GetPreciousObjectsState(self.project, self.opt))