heptapod-ci: (hopefully) fix the pipeline savings system
There is no easy way for me to test this outside of the actual repo since
it would require setting up `heptapod-runner` locally, making a Git repo
with the right changes, etc. It's not worth my time at this point.
If this fails, I'll try to ask for help from Georges, the maintainer
of Heptapod.
Set up
$ hg init repo
$ cd repo
$ echo a > a
$ hg add a
$ hg commit -m a
Try to import an empty patch
$ hg import --no-commit - <<EOF
> EOF
applying patch from stdin
abort: stdin: no diffs found
[10]
No dirstate backups are left behind
$ ls .hg/dirstate* | sort
.hg/dirstate