BranchHasPendingWrites: The source branch has pending writes.

Hi,

Got https://oops.canonical.com/?oopsid=OOPS-b622eab540a5375ca660d5a230cfcdbf

Launchpad encountered an internal error during the following operation:
generating the diff for a merge proposal. It was logged with id
OOPS-b622eab540a5375ca660d5a230cfcdbf. Sorry for the inconvenience.

  BranchHasPendingWrites: The source branch has pending writes.

    Traceback (most recent call last):
  Module lazr.jobrunner.jobrunner, line 194, in runJobHandleError
    self.runJob(job, fallback)
  Module lp.services.job.runner, line 289, in runJob
    super(BaseJobRunner, self).runJob(IRunnableJob(job), fallback)
  Module lazr.jobrunner.jobrunner, line 162, in runJob
    job.run()
  Module lp.code.model.branchmergeproposaljob, line 369, in run
    self.checkReady()
  Module lp.code.model.branchmergeproposaljob, line 362, in checkReady
    'The source branch has pending writes.')
BranchHasPendingWrites: The source branch has pending writes.

Which seems to have been when submitting a merge proposal.

It seems the branch was being updated while I submitted it, in which case Launchpad should probably retry?

Thanks,