Default branch can't always be determined

[jhauberg]

The function default_branch rely on the existence of a HEAD ref in refs/remotes/origin to determine default branch name. However, this ref does not always, nor does it have to, exist (see this answer).

gitdoctor/doctor/repo.py

Lines 44 to 51 in ecb0e4c

	def default_branch() -> str:
	""" Return the symbolic reference to the default branch. """
	result = subprocess.run([
	'git', 'symbolic-ref', '--short', 'refs/remotes/origin/HEAD'],
	check=True, # print stacktrace on non-zero exit status
	stdout=subprocess.PIPE, # capture stdout
	stderr=subprocess.DEVNULL) # ignore stderr

In a repository where the refs/remotes/origin/HEAD does not exist, this error will trigger:

$ git symbolic-ref --short refs/remotes/origin/HEAD
fatal: ref refs/remotes/origin/HEAD is not a symbolic ref

[jhauberg]

So the real problem here, is that there is no such thing as a "default branch". It is a thing on GitHub, sure, but in a plain git context, there is no default branch. There is master to begin with, but that could just be deleted or named differently.

[jhauberg]

This might be a way to go:

$ git remote
origin
$ git remote show origin
* remote origin
  Fetch URL: https://github.com/jhauberg/gitdoctor.git
  Push  URL: https://github.com/jhauberg/gitdoctor.git
  HEAD branch: master
  Remote branches:
    develop tracked
    master  tracked
  Local branches configured for 'git pull':
    develop merges with remote develop
    master  merges with remote master
  Local refs configured for 'git push':
    develop pushes to develop (up to date)
    master  pushes to master  (up to date)

In particular, the HEAD branch: master part.

[jhauberg]

Seems to work. Closing for now.