Repository.checkout('refs/heads/<head name>') with an orphan master branch results in exception #669
Description
In my repository, master has no commits (nor will it ever) and it seems like, without checking, Repository.checkout() uses the current branch (which might be the orphaned master)'s head, but I don't understand why, as from_ is not referred to again in the file.
head = self.lookup_reference('HEAD')
if head.type == C.GIT_REF_SYMBOLIC:
from_ = self.head.shorthand
else:
from_ = head.target.hex
In my repository, this results in an exception and ubuntu/devel is present but not switched to.
$ git branch
ubuntu/devel
Traceback (most recent call last):
File "/home/nacc/work/usd-importer/usd/git_repository.py", line 453, in checkout
self._local_repo.checkout('refs/heads/%s' % ref)
File "/usr/lib/python3/dist-packages/pygit2/repository.py", line 284, in checkout
from_ = self.head.shorthand
_pygit2.GitError: Reference 'refs/heads/master' not found