init: make bad --repo-rev settings more clear

If the user passes a bad --repo-rev setting in a new checkout, add a
tip to the error message that their option is probably bad instead of
just saying "unable to resolve".

If the user has already initialized a checkout, we'd display a raw
traceback which would confuse them.  Swallow that and also include
the --repo-rev tip.

Bug: https://crbug.com/gerrit/15610
Change-Id: I5d72513c7b37bf9bb5d19862fcdfaf0d1f44e886
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/328820
Reviewed-by: Jack Neus <jackneus@google.com>
Tested-by: Mike Frysinger <vapier@google.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/subcmds/init.py b/subcmds/init.py
index e2f34cc8..b0db76a4 100644
--- a/subcmds/init.py
+++ b/subcmds/init.py
@@ -520,8 +520,12 @@ to update the working directory files.
     # Handle new --repo-rev requests.
     if opt.repo_rev:
       wrapper = Wrapper()
-      remote_ref, rev = wrapper.check_repo_rev(
-          rp.gitdir, opt.repo_rev, repo_verify=opt.repo_verify, quiet=opt.quiet)
+      try:
+        remote_ref, rev = wrapper.check_repo_rev(
+            rp.gitdir, opt.repo_rev, repo_verify=opt.repo_verify, quiet=opt.quiet)
+      except wrapper.CloneFailure:
+        print('fatal: double check your --repo-rev setting.', file=sys.stderr)
+        sys.exit(1)
       branch = rp.GetBranch('default')
       branch.merge = remote_ref
       rp.work_git.reset('--hard', rev)