[git_trace2] Add logs for critical cmds

Trace logs emitted from repo are not useful on error for many critical
commands. This change adds errors for critical commands to trace logs.

Change-Id: Ideb9358bee31e540bd84a94327a09ff9b0246a77
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/373814
Reviewed-by: Joanna Wang <jojwang@google.com>
Tested-by: Josip Sokcevic <sokcevic@google.com>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>
Reviewed-by: Gavin Mak <gavinmak@google.com>

git_trace2_event_log.py

@@ -198,9 +198,11 @@ class EventLog(object):
             event["value"] = value
             self._log.append(event)
 
-    def ErrorEvent(self, msg, fmt):
+    def ErrorEvent(self, msg, fmt=None):
         """Append a 'error' event to the current log."""
         error_event = self._CreateEventDict("error")
+        if fmt is None:
+            fmt = msg
         error_event["msg"] = msg
         error_event["fmt"] = fmt
         self._log.append(error_event)

subcmds/init.py

@@ -341,10 +341,12 @@ to update the working directory files.
                     quiet=opt.quiet,
                 )
             except wrapper.CloneFailure:
+                err_msg = "fatal: double check your --repo-rev setting."
                 print(
-                    "fatal: double check your --repo-rev setting.",
+                    err_msg,
                     file=sys.stderr,
                 )
+                self.git_event_log.ErrorEvent(err_msg)
                 sys.exit(1)
             branch = rp.GetBranch("default")
             branch.merge = remote_ref

subcmds/rebase.py

@@ -206,7 +206,9 @@ branch but need to incorporate new upstream changes "underneath" them.
                     ret += 1
 
         if ret:
-            out.fail("%i projects had errors", ret)
+            msg_fmt = "%d projects had errors"
+            self.git_event_log.ErrorEvent(msg_fmt % (ret), msg_fmt)
+            out.fail(msg_fmt, ret)
             out.nl()
 
         return ret

subcmds/start.py

@@ -168,4 +168,6 @@ revision specified in the manifest.
                     % (p.RelPath(local=opt.this_manifest_only), nb),
                     file=sys.stderr,
                 )
+            msg_fmt = "cannot start %d project(s)"
+            self.git_event_log.ErrorEvent(msg_fmt % (len(err)), msg_fmt)
             sys.exit(1)

subcmds/sync.py

@@ -1695,32 +1695,29 @@ later is required to fix a server side protocol bug.
 
         # If we saw an error, exit with code 1 so that other scripts can check.
         if err_event.is_set():
-            print("\nerror: Unable to fully sync the tree.", file=sys.stderr)
+            # Add a new line so it's easier to read.
+            print("\n", file=sys.stderr)
+
+            def print_and_log(err_msg):
+                self.git_event_log.ErrorEvent(err_msg)
+                print(err_msg, file=sys.stderr)
+
+            print_and_log("error: Unable to fully sync the tree")
             if err_network_sync:
-                print(
-                    "error: Downloading network changes failed.",
-                    file=sys.stderr,
-                )
+                print_and_log("error: Downloading network changes failed.")
             if err_update_projects:
-                print(
-                    "error: Updating local project lists failed.",
-                    file=sys.stderr,
-                )
+                print_and_log("error: Updating local project lists failed.")
             if err_update_linkfiles:
-                print(
-                    "error: Updating copyfiles or linkfiles failed.",
-                    file=sys.stderr,
-                )
+                print_and_log("error: Updating copyfiles or linkfiles failed.")
             if err_checkout:
-                print(
-                    "error: Checking out local projects failed.",
-                    file=sys.stderr,
-                )
+                print_and_log("error: Checking out local projects failed.")
                 if err_results:
+                    # Don't log repositories, as it may contain sensitive info.
                     print(
                         "Failing repos:\n%s" % "\n".join(err_results),
                         file=sys.stderr,
                     )
+            # Not useful to log.
             print(
                 'Try re-running with "-j1 --fail-fast" to exit at the first '
                 "error.",

subcmds/upload.py

@@ -657,6 +657,7 @@ Gerrit Code Review:  https://www.gerritcodereview.com/
 
                 branch.uploaded = True
             except UploadError as e:
+                self.git_event_log.ErrorEvent("upload error: " + str(e))
                 branch.error = e
                 branch.uploaded = False
                 have_errors = True