Refactor errors for sync command

Per discussion in go/repo-error-update updated aggregated and exit
errors for sync command.

Aggregated errors are errors that result in eventual command failure.
Exit errors are errors that result in immediate command failure.

Also updated main.py to log aggregated and exit errors to git sessions
log

Bug: b/293344017
Change-Id: I77a21f14da32fe2e68c16841feb22de72e86a251
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/379614
Reviewed-by: Aravind Vasudevan <aravindvasudev@google.com>
Tested-by: Jason Chang <jasonnc@google.com>
Commit-Queue: Jason Chang <jasonnc@google.com>

1 files changed, 196 insertions, 87 deletions

diff --git a/project.py b/project.py
index 83f3eff9..b268007d 100644
--- a/project.py
+++ b/project.py
@@ -26,7 +26,7 @@ import sys
 import tarfile
 import tempfile
 import time
-from typing import NamedTuple
+from typing import NamedTuple, List
 import urllib.parse
 
 from color import Coloring
@@ -41,7 +41,12 @@ from git_config import (
 )
 import git_superproject
 from git_trace2_event_log import EventLog
-from error import GitError, UploadError, DownloadError
+from error import (
+    GitError,
+    UploadError,
+    DownloadError,
+    RepoError,
+)
 from error import ManifestInvalidRevisionError, ManifestInvalidPathError
 from error import NoManifestException, ManifestParseError
 import platform_utils
@@ -54,11 +59,33 @@ 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
+    # Error from SyncNetworkHalf
+    error: Exception = None
+
+    @property
+    def success(self) -> bool:
+        return not self.error
+
+
+class SyncNetworkHalfError(RepoError):
+    """Failure trying to sync."""
+
+
+class DeleteWorktreeError(RepoError):
+    """Failure to delete worktree."""
+
+    def __init__(
+        self, *args, aggregate_errors: List[Exception] = None, **kwargs
+    ) -> None:
+        super().__init__(*args, **kwargs)
+        self.aggregate_errors = aggregate_errors or []
+
+
+class DeleteDirtyWorktreeError(DeleteWorktreeError):
+    """Failure to delete worktree due to uncommitted changes."""
 
 
 # Maximum sleep time allowed during retries.
@@ -1070,13 +1097,19 @@ class Project(object):
         if branch is None:
             branch = self.CurrentBranch
         if branch is None:
-            raise GitError("not currently on a branch")
+            raise GitError("not currently on a branch", project=self.name)
 
         branch = self.GetBranch(branch)
         if not branch.LocalMerge:
-            raise GitError("branch %s does not track a remote" % branch.name)
+            raise GitError(
+                "branch %s does not track a remote" % branch.name,
+                project=self.name,
+            )
         if not branch.remote.review:
-            raise GitError("remote %s has no review url" % branch.remote.name)
+            raise GitError(
+                "remote %s has no review url" % branch.remote.name,
+                project=self.name,
+            )
 
         # Basic validity check on label syntax.
         for label in labels:
@@ -1193,11 +1226,18 @@ class Project(object):
         """
         if archive and not isinstance(self, MetaProject):
             if self.remote.url.startswith(("http://", "https://")):
+                msg_template = (
+                    "%s: Cannot fetch archives from http/https remotes."
+                )
+                msg_args = self.name
+                msg = msg_template % msg_args
                 _error(
-                    "%s: Cannot fetch archives from http/https remotes.",
-                    self.name,
+                    msg_template,
+                    msg_args,
+                )
+                return SyncNetworkHalfResult(
+                    False, SyncNetworkHalfError(msg, project=self.name)
                 )
-                return SyncNetworkHalfResult(False, False)
 
             name = self.relpath.replace("\\", "/")
             name = name.replace("/", "_")
@@ -1208,19 +1248,25 @@ class Project(object):
                 self._FetchArchive(tarpath, cwd=topdir)
             except GitError as e:
                 _error("%s", e)
-                return SyncNetworkHalfResult(False, False)
+                return SyncNetworkHalfResult(False, e)
 
             # From now on, we only need absolute tarpath.
             tarpath = os.path.join(topdir, tarpath)
 
             if not self._ExtractArchive(tarpath, path=topdir):
-                return SyncNetworkHalfResult(False, True)
+                return SyncNetworkHalfResult(
+                    True,
+                    SyncNetworkHalfError(
+                        f"Unable to Extract Archive {tarpath}",
+                        project=self.name,
+                    ),
+                )
             try:
                 platform_utils.remove(tarpath)
             except OSError as e:
                 _warn("Cannot remove archive %s: %s", tarpath, str(e))
             self._CopyAndLinkFiles()
-            return SyncNetworkHalfResult(True, True)
+            return SyncNetworkHalfResult(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
@@ -1310,23 +1356,35 @@ class Project(object):
             )
         ):
             remote_fetched = True
-            if not self._RemoteFetch(
-                initial=is_new,
-                quiet=quiet,
-                verbose=verbose,
-                output_redir=output_redir,
-                alt_dir=alt_dir,
-                current_branch_only=current_branch_only,
-                tags=tags,
-                prune=prune,
-                depth=depth,
-                submodules=submodules,
-                force_sync=force_sync,
-                ssh_proxy=ssh_proxy,
-                clone_filter=clone_filter,
-                retry_fetches=retry_fetches,
-            ):
-                return SyncNetworkHalfResult(False, remote_fetched)
+            try:
+                if not self._RemoteFetch(
+                    initial=is_new,
+                    quiet=quiet,
+                    verbose=verbose,
+                    output_redir=output_redir,
+                    alt_dir=alt_dir,
+                    current_branch_only=current_branch_only,
+                    tags=tags,
+                    prune=prune,
+                    depth=depth,
+                    submodules=submodules,
+                    force_sync=force_sync,
+                    ssh_proxy=ssh_proxy,
+                    clone_filter=clone_filter,
+                    retry_fetches=retry_fetches,
+                ):
+                    return SyncNetworkHalfResult(
+                        remote_fetched,
+                        SyncNetworkHalfError(
+                            f"Unable to remote fetch project {self.name}",
+                            project=self.name,
+                        ),
+                    )
+            except RepoError as e:
+                return SyncNetworkHalfResult(
+                    remote_fetched,
+                    e,
+                )
 
         mp = self.manifest.manifestProject
         dissociate = mp.dissociate
@@ -1346,7 +1404,12 @@ class Project(object):
                 if p.stdout and output_redir:
                     output_redir.write(p.stdout)
                 if p.Wait() != 0:
-                    return SyncNetworkHalfResult(False, remote_fetched)
+                    return SyncNetworkHalfResult(
+                        remote_fetched,
+                        GitError(
+                            "Unable to repack alternates", project=self.name
+                        ),
+                    )
                 platform_utils.remove(alternates_file)
 
         if self.worktree:
@@ -1356,7 +1419,7 @@ class Project(object):
             platform_utils.remove(
                 os.path.join(self.gitdir, "FETCH_HEAD"), missing_ok=True
             )
-        return SyncNetworkHalfResult(True, remote_fetched)
+        return SyncNetworkHalfResult(remote_fetched)
 
     def PostRepoUpgrade(self):
         self._InitHooks()
@@ -1409,16 +1472,27 @@ class Project(object):
 
         self.revisionId = revisionId
 
-    def Sync_LocalHalf(self, syncbuf, force_sync=False, submodules=False):
+    def Sync_LocalHalf(
+        self, syncbuf, force_sync=False, submodules=False, errors=None
+    ):
         """Perform only the local IO portion of the sync process.
 
         Network access is not required.
         """
+        if errors is None:
+            errors = []
+
+        def fail(error: Exception):
+            errors.append(error)
+            syncbuf.fail(self, error)
+
         if not os.path.exists(self.gitdir):
-            syncbuf.fail(
-                self,
-                "Cannot checkout %s due to missing network sync; Run "
-                "`repo sync -n %s` first." % (self.name, self.name),
+            fail(
+                LocalSyncFail(
+                    "Cannot checkout %s due to missing network sync; Run "
+                    "`repo sync -n %s` first." % (self.name, self.name),
+                    project=self.name,
+                )
             )
             return
 
@@ -1438,10 +1512,12 @@ class Project(object):
             )
             bad_paths = paths & PROTECTED_PATHS
             if bad_paths:
-                syncbuf.fail(
-                    self,
-                    "Refusing to checkout project that writes to protected "
-                    "paths: %s" % (", ".join(bad_paths),),
+                fail(
+                    LocalSyncFail(
+                        "Refusing to checkout project that writes to protected "
+                        "paths: %s" % (", ".join(bad_paths),),
+                        project=self.name,
+                    )
                 )
                 return
 
@@ -1466,7 +1542,7 @@ class Project(object):
             # Currently on a detached HEAD.  The user is assumed to
             # not have any local modifications worth worrying about.
             if self.IsRebaseInProgress():
-                syncbuf.fail(self, _PriorSyncFailedError())
+                fail(_PriorSyncFailedError(project=self.name))
                 return
 
             if head == revid:
@@ -1486,7 +1562,7 @@ class Project(object):
                 if submodules:
                     self._SyncSubmodules(quiet=True)
             except GitError as e:
-                syncbuf.fail(self, e)
+                fail(e)
                 return
             self._CopyAndLinkFiles()
             return
@@ -1511,7 +1587,7 @@ class Project(object):
                 if submodules:
                     self._SyncSubmodules(quiet=True)
             except GitError as e:
-                syncbuf.fail(self, e)
+                fail(e)
                 return
             self._CopyAndLinkFiles()
             return
@@ -1534,10 +1610,13 @@ class Project(object):
                     # The user has published this branch and some of those
                     # commits are not yet merged upstream.  We do not want
                     # to rewrite the published commits so we punt.
-                    syncbuf.fail(
-                        self,
-                        "branch %s is published (but not merged) and is now "
-                        "%d commits behind" % (branch.name, len(upstream_gain)),
+                    fail(
+                        LocalSyncFail(
+                            "branch %s is published (but not merged) and is "
+                            "now %d commits behind"
+                            % (branch.name, len(upstream_gain)),
+                            project=self.name,
+                        )
                     )
                 return
             elif pub == head:
@@ -1565,7 +1644,7 @@ class Project(object):
             return
 
         if self.IsDirty(consider_untracked=False):
-            syncbuf.fail(self, _DirtyError())
+            fail(_DirtyError(project=self.name))
             return
 
         # If the upstream switched on us, warn the user.
@@ -1615,7 +1694,7 @@ class Project(object):
                     self._SyncSubmodules(quiet=True)
                 self._CopyAndLinkFiles()
             except GitError as e:
-                syncbuf.fail(self, e)
+                fail(e)
                 return
         else:
             syncbuf.later1(self, _doff)
@@ -1687,12 +1766,12 @@ class Project(object):
                     file=sys.stderr,
                 )
             else:
-                print(
-                    "error: %s: Cannot remove project: uncommitted changes are "
-                    "present.\n" % (self.RelPath(local=False),),
-                    file=sys.stderr,
+                msg = (
+                    "error: %s: Cannot remove project: uncommitted"
+                    "changes are present.\n" % self.RelPath(local=False)
                 )
-                return False
+                print(msg, file=sys.stderr)
+                raise DeleteDirtyWorktreeError(msg, project=self)
 
         if not quiet:
             print(
@@ -1745,12 +1824,13 @@ class Project(object):
                     % (self.RelPath(local=False),),
                     file=sys.stderr,
                 )
-                return False
+                raise DeleteWorktreeError(aggregate_errors=[e])
 
         # Delete everything under the worktree, except for directories that
         # contain another git project.
         dirs_to_remove = []
         failed = False
+        errors = []
         for root, dirs, files in platform_utils.walk(self.worktree):
             for f in files:
                 path = os.path.join(root, f)
@@ -1763,6 +1843,7 @@ class Project(object):
                             file=sys.stderr,
                         )
                         failed = True
+                        errors.append(e)
             dirs[:] = [
                 d
                 for d in dirs
@@ -1784,6 +1865,7 @@ class Project(object):
                             file=sys.stderr,
                         )
                         failed = True
+                        errors.append(e)
             elif not platform_utils.listdir(d):
                 try:
                     platform_utils.rmdir(d)
@@ -1794,6 +1876,7 @@ class Project(object):
                             file=sys.stderr,
                         )
                         failed = True
+                        errors.append(e)
         if failed:
             print(
                 "error: %s: Failed to delete obsolete checkout."
@@ -1804,7 +1887,7 @@ class Project(object):
                 "       Remove manually, then run `repo sync -l`.",
                 file=sys.stderr,
             )
-            return False
+            raise DeleteWorktreeError(aggregate_errors=errors)
 
         # Try deleting parent dirs if they are empty.
         path = self.worktree
@@ -2264,11 +2347,14 @@ class Project(object):
         cmd.append(self.revisionExpr)
 
         command = GitCommand(
-            self, cmd, cwd=cwd, capture_stdout=True, capture_stderr=True
+            self,
+            cmd,
+            cwd=cwd,
+            capture_stdout=True,
+            capture_stderr=True,
+            verify_command=True,
         )
-
-        if command.Wait() != 0:
-            raise GitError("git archive %s: %s" % (self.name, command.stderr))
+        command.Wait()
 
     def _RemoteFetch(
         self,
@@ -2289,7 +2375,7 @@ class Project(object):
         retry_fetches=2,
         retry_sleep_initial_sec=4.0,
         retry_exp_factor=2.0,
-    ):
+    ) -> bool:
         is_sha1 = False
         tag_name = None
         # The depth should not be used when fetching to a mirror because
@@ -2473,6 +2559,7 @@ class Project(object):
         retry_cur_sleep = retry_sleep_initial_sec
         ok = prune_tried = False
         for try_n in range(retry_fetches):
+            verify_command = try_n == retry_fetches - 1
             gitcmd = GitCommand(
                 self,
                 cmd,
@@ -2481,6 +2568,7 @@ class Project(object):
                 ssh_proxy=ssh_proxy,
                 merge_output=True,
                 capture_stdout=quiet or bool(output_redir),
+                verify_command=verify_command,
             )
             if gitcmd.stdout and not quiet and output_redir:
                 output_redir.write(gitcmd.stdout)
@@ -2732,7 +2820,9 @@ class Project(object):
         cmd.append("--")
         if GitCommand(self, cmd).Wait() != 0:
             if self._allrefs:
-                raise GitError("%s checkout %s " % (self.name, rev))
+                raise GitError(
+                    "%s checkout %s " % (self.name, rev), project=self.name
+                )
 
     def _CherryPick(self, rev, ffonly=False, record_origin=False):
         cmd = ["cherry-pick"]
@@ -2744,7 +2834,9 @@ class Project(object):
         cmd.append("--")
         if GitCommand(self, cmd).Wait() != 0:
             if self._allrefs:
-                raise GitError("%s cherry-pick %s " % (self.name, rev))
+                raise GitError(
+                    "%s cherry-pick %s " % (self.name, rev), project=self.name
+                )
 
     def _LsRemote(self, refs):
         cmd = ["ls-remote", self.remote.name, refs]
@@ -2760,7 +2852,9 @@ class Project(object):
         cmd.append("--")
         if GitCommand(self, cmd).Wait() != 0:
             if self._allrefs:
-                raise GitError("%s revert %s " % (self.name, rev))
+                raise GitError(
+                    "%s revert %s " % (self.name, rev), project=self.name
+                )
 
     def _ResetHard(self, rev, quiet=True):
         cmd = ["reset", "--hard"]
@@ -2768,7 +2862,9 @@ class Project(object):
             cmd.append("-q")
         cmd.append(rev)
         if GitCommand(self, cmd).Wait() != 0:
-            raise GitError("%s reset --hard %s " % (self.name, rev))
+            raise GitError(
+                "%s reset --hard %s " % (self.name, rev), project=self.name
+            )
 
     def _SyncSubmodules(self, quiet=True):
         cmd = ["submodule", "update", "--init", "--recursive"]
@@ -2776,7 +2872,8 @@ class Project(object):
             cmd.append("-q")
         if GitCommand(self, cmd).Wait() != 0:
             raise GitError(
-                "%s submodule update --init --recursive " % self.name
+                "%s submodule update --init --recursive " % self.name,
+                project=self.name,
             )
 
     def _Rebase(self, upstream, onto=None):
@@ -2785,14 +2882,18 @@ class Project(object):
             cmd.extend(["--onto", onto])
         cmd.append(upstream)
         if GitCommand(self, cmd).Wait() != 0:
-            raise GitError("%s rebase %s " % (self.name, upstream))
+            raise GitError(
+                "%s rebase %s " % (self.name, upstream), project=self.name
+            )
 
     def _FastForward(self, head, ffonly=False):
         cmd = ["merge", "--no-stat", head]
         if ffonly:
             cmd.append("--ff-only")
         if GitCommand(self, cmd).Wait() != 0:
-            raise GitError("%s merge %s " % (self.name, head))
+            raise GitError(
+                "%s merge %s " % (self.name, head), project=self.name
+            )
 
     def _InitGitDir(self, mirror_git=None, force_sync=False, quiet=False):
         init_git_dir = not os.path.exists(self.gitdir)
@@ -2964,7 +3065,9 @@ class Project(object):
                     try:
                         os.link(stock_hook, dst)
                     except OSError:
-                        raise GitError(self._get_symlink_error_message())
+                        raise GitError(
+                            self._get_symlink_error_message(), project=self.name
+                        )
                 else:
                     raise
 
@@ -3065,7 +3168,8 @@ class Project(object):
                         "work tree. If you're comfortable with the "
                         "possibility of losing the work tree's git metadata,"
                         " use `repo sync --force-sync {0}` to "
-                        "proceed.".format(self.RelPath(local=False))
+                        "proceed.".format(self.RelPath(local=False)),
+                        project=self.name,
                     )
 
     def _ReferenceGitDir(self, gitdir, dotgit, copy_all):
@@ -3175,7 +3279,7 @@ class Project(object):
 
         # If using an old layout style (a directory), migrate it.
         if not platform_utils.islink(dotgit) and platform_utils.isdir(dotgit):
-            self._MigrateOldWorkTreeGitDir(dotgit)
+            self._MigrateOldWorkTreeGitDir(dotgit, project=self.name)
 
         init_dotgit = not os.path.exists(dotgit)
         if self.use_git_worktrees:
@@ -3205,7 +3309,8 @@ class Project(object):
                 cmd = ["read-tree", "--reset", "-u", "-v", HEAD]
                 if GitCommand(self, cmd).Wait() != 0:
                     raise GitError(
-                        "Cannot initialize work tree for " + self.name
+                        "Cannot initialize work tree for " + self.name,
+                        project=self.name,
                     )
 
                 if submodules:
@@ -3213,7 +3318,7 @@ class Project(object):
                 self._CopyAndLinkFiles()
 
     @classmethod
-    def _MigrateOldWorkTreeGitDir(cls, dotgit):
+    def _MigrateOldWorkTreeGitDir(cls, dotgit, project=None):
         """Migrate the old worktree .git/ dir style to a symlink.
 
         This logic specifically only uses state from |dotgit| to figure out
@@ -3223,7 +3328,9 @@ class Project(object):
         """
         # Figure out where in .repo/projects/ it's pointing to.
         if not os.path.islink(os.path.join(dotgit, "refs")):
-            raise GitError(f"{dotgit}: unsupported checkout state")
+            raise GitError(
+                f"{dotgit}: unsupported checkout state", project=project
+            )
         gitdir = os.path.dirname(os.path.realpath(os.path.join(dotgit, "refs")))
 
         # Remove known symlink paths that exist in .repo/projects/.
@@ -3271,7 +3378,10 @@ class Project(object):
                         f"{dotgit_path}: unknown file; please file a bug"
                     )
         if unknown_paths:
-            raise GitError("Aborting migration: " + "\n".join(unknown_paths))
+            raise GitError(
+                "Aborting migration: " + "\n".join(unknown_paths),
+                project=project,
+            )
 
         # Now walk the paths and sync the .git/ to .repo/projects/.
         for name in platform_utils.listdir(dotgit):
@@ -3537,12 +3647,9 @@ class Project(object):
                 gitdir=self._gitdir,
                 capture_stdout=True,
                 capture_stderr=True,
+                verify_command=True,
             )
-            if p.Wait() != 0:
-                raise GitError(
-                    "%s rev-list %s: %s"
-                    % (self._project.name, str(args), p.stderr)
-                )
+            p.Wait()
             return p.stdout.splitlines()
 
         def __getattr__(self, name):
@@ -3588,11 +3695,9 @@ class Project(object):
                     gitdir=self._gitdir,
                     capture_stdout=True,
                     capture_stderr=True,
+                    verify_command=True,
                 )
-                if p.Wait() != 0:
-                    raise GitError(
-                        "%s %s: %s" % (self._project.name, name, p.stderr)
-                    )
+                p.Wait()
                 r = p.stdout
                 if r.endswith("\n") and r.index("\n") == len(r) - 1:
                     return r[:-1]
@@ -3601,12 +3706,16 @@ class Project(object):
             return runner
 
 
-class _PriorSyncFailedError(Exception):
+class LocalSyncFail(RepoError):
+    """Default error when there is an Sync_LocalHalf error."""
+
+
+class _PriorSyncFailedError(LocalSyncFail):
     def __str__(self):
         return "prior sync failed; rebase still in progress"
 
 
-class _DirtyError(Exception):
+class _DirtyError(LocalSyncFail):
     def __str__(self):
         return "contains uncommitted changes"