1 files changed, 27 insertions, 11 deletions

diff --git a/subcmds/start.py b/subcmds/start.py
index f6355126..67ac7df9 100644
--- a/subcmds/start.py
+++ b/subcmds/start.py
@@ -21,7 +21,18 @@ from git_config import IsImmutable
 from git_command import git
 import gitc_utils
 from progress import Progress
-from project import SyncBuffer
+from project import SyncBuffer, Project
+from typing import NamedTuple
+from error import RepoExitError
+
+
+class ExecuteOneResult(NamedTuple):
+    project: Project
+    error: Exception
+
+
+class StartError(RepoExitError):
+    """Exit error for failed start command."""
 
 
 class Start(Command):
@@ -73,6 +84,7 @@ revision specified in the manifest.
         # a change, then we can't push back to it. Substitute with
         # dest_branch, if defined; or with manifest default revision instead.
         branch_merge = ""
+        error = None
         if IsImmutable(project.revisionExpr):
             if project.dest_branch:
                 branch_merge = project.dest_branch
@@ -80,7 +92,7 @@ revision specified in the manifest.
                 branch_merge = self.manifest.default.revisionExpr
 
         try:
-            ret = project.StartBranch(
+            project.StartBranch(
                 nb, branch_merge=branch_merge, revision=revision
             )
         except Exception as e:
@@ -88,11 +100,12 @@ revision specified in the manifest.
                 "error: unable to checkout %s: %s" % (project.name, e),
                 file=sys.stderr,
             )
-            ret = False
-        return (ret, project)
+            error = e
+        return ExecuteOneResult(project, error)
 
     def Execute(self, opt, args):
         nb = args[0]
+        err_projects = []
         err = []
         projects = []
         if not opt.all:
@@ -146,9 +159,10 @@ revision specified in the manifest.
             pm.end()
 
         def _ProcessResults(_pool, pm, results):
-            for result, project in results:
-                if not result:
-                    err.append(project)
+            for result in results:
+                if result.error:
+                    err_projects.append(result.project)
+                    err.append(result.error)
                 pm.update(msg="")
 
         self.ExecuteInParallel(
@@ -161,13 +175,15 @@ revision specified in the manifest.
             ),
         )
 
-        if err:
-            for p in err:
+        if err_projects:
+            for p in err_projects:
                 print(
                     "error: %s/: cannot start %s"
                     % (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)
+            self.git_event_log.ErrorEvent(
+                msg_fmt % (len(err_projects)), msg_fmt
+            )
+            raise StartError(aggregate_errors=err)