`tar_git` service fails when repo to clone was once private

[nephros]

I am getting the error message from a service run of tar_git:

Files could not be expanded: service error: ERROR: couldn't clone reponame

service tar_git failed:
Handling reponame
fatal: not a git repository (or any parent up to mount point /)
Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).
fatal: repository '/data/service/tar_git/https___gitlab.com_nephros/reponame' does not exist
ERROR: couldn't clone reponame

Steps to reproduce:

1. on GitLAB, create a new repo
2. when creating, make sure to create a 'private' visibility
3. commit some files that should wor with tar_git service
4. create a new package at OBS
5. create a service file pulling from the above repo
6. observe the cloning error as expected
7. on Gitlab project settings, change visibility from private to public
8. trigger the service again
9. service cannot clone still
10. use any other tool to clone that repo, confirm that it works normally.

[lbt]

tar_git doesn't appear to clean up properly in /data/service/tar_git/https___gitlab.com_nephros (in this case)

Manual cleanup allowed the service to run.
Issue left open in case it recurs.

[Olf0]

@nephros & @lbt, I believe it makes more sense to primarily handle an issue at the issue tracker of the corresponding source code repository, so I created MeeGoIntegration/obs-service-tar-git#3

IMO it still makes sense to keep this issue open here (also) as a reference (as long MeeGoIntegration/obs-service-tar-git#3 is not resolved), so other people affected may find it more easily (I assume @nephros originally also did not know where it is).