usage of fetch

[bertsky]

I am having difficulty understanding how to use fetch. If I do not pass a checkout_dir (which I would expect to be generated from the last path component of git_repo as in git clone URL), then it says Can't checkout into a bare repo. If I do pass some checkout_dir, then I run into this:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.8/site-packages/git_lfs/__init__.py", line 165, in fetch
    with TempDir(dir=checkout_dir) as d:
  File "/usr/lib/python3.8/contextlib.py", line 113, in __enter__
    return next(self.gen)
  File "/usr/lib/python3.8/site-packages/git_lfs/utils.py", line 33, in TempDir
    d = mkdtemp(**kw)
  File "/usr/lib/python3.8/tempfile.py", line 498, in mkdtemp
    _os.mkdir(file, 0o700)
FileNotFoundError: [Errno 2] No such file or directory: 'test/tmp9jicu15s'

So this obviously expects an existing directory. Why?

[Changaco]

Requiring an existing directory was most likely unintentional. Again, I encourage you to make a pull request to fix the problem.

[bertsky]

Ok, I will, but allow me to understand how usage was meant to work.

git-lfs-fetch.py/git_lfs/__init__.py

Lines 163 to 169 in 23026ff

	checkout_git_dir = checkout_dir+'/.git'
	if not os.path.isdir(checkout_git_dir):
	with TempDir(dir=checkout_dir) as d:
	check_output(['git', 'clone', '-ns', git_repo, d], stderr=STDOUT)
	os.rename(d+'/.git', checkout_git_dir)
	with in_dir(checkout_dir):
	check_output(['git', 'reset', 'HEAD'])

Why the os.rename? Why even a temporary directory in the first place?

[Changaco]

Creating a temporary file or directory, then renaming it, is a way of making changes atomically.

I don't remember if the code was written this way merely as a precaution or if I actually needed this “safety” at the time.

[bertsky]

Understood. It would help if you could divulge one concrete example of a call (API or CLI) that used to succeed. I'm sure I can take it from there and reconstruct the intended implementation.

[Changaco]

The call was python -m git_lfs -vv ~/git/$OPENSHIFT_APP_NAME.git $OPENSHIFT_REPO_DIR.

[bertsky]

The call was python -m git_lfs -vv ~/git/$OPENSHIFT_APP_NAME.git $OPENSHIFT_REPO_DIR.

Oh, then my impression that this was also meant for remote repos (first cloning https or git URLs) was wrong to begin with?

[Changaco]

The code was never meant to be invoked with URLs of remote repositories.