rebase abort: unknown revision

[Ethan Tira-Thompson]

Running rebase, it aborts complaining about an unknown revision.  hg verify passes, I can tell from looking at the --debug output that the problem is from a subrepo:

updating: .hgsubstate 1/12 files (8.33%)
subrepo merge 09230bb1e4a2+ 25eab148daac ab2fee183998
  subrepo project: both sides changed, merge with project:6ade3a0e0016e5262a4b8904426d6aa9a56b596c:hg
pulling subrepo project from /Users/ejt/todo/Tekkotsu/project
searching for changes
no changes found
abort: unknown revision '6ade3a0e0016e5262a4b8904426d6aa9a56b596c'!

What probably happened here is:
1. Once upon a time, I ran 'hg commit' in the main repo
2. Commit processed the subrepos to commit their changes
3. I say, “crap!”... the subrepo changes were temporary and unrelated (no thanks to Issue1813, status not including subrepos by default)
4. I clean up and commit again to fix .hgsubstate
5. I push changes from the main repo, but throw away the changes in the subrepo

So now the .hgsubstate history contains an ‘invalid' revision id in its history.  What can I do?  Ideally, I just want rebase to ignore this missing revision and continue on its way, there aren’t any changes to rebase in the subrepo anyway.

Thanks,
 -Ethan