setuptools_scm incompatible with default actions/checkout@v2

[ddelange]

actions/checkout@v2 no longer fetches tags by default, rather only a single commit, $GITHUB_REF (actions/checkout#100).

Hence, fetch-depth: 0 is needed for the proper version to be detected (unless GH actions runs was triggered on a tag@HEAD):

    steps:
    - uses: actions/checkout@v2
      with:
        fetch-depth: 0

This however slows down checkout significantly on big repos (actions/checkout#258).

Only fetching tags (manually) does not solve the problem:

    steps:
    - uses: actions/checkout@v2

    - name: Fetch tags
      # fetch all tags for changelog and pip install
      run: git fetch origin --depth=1 +refs/tags/*:refs/tags/*

What would be the minimum amount of info to fetch for setuptools_scm to pick up the right tag? Any explanation why it doesn't detect version after running git fetch origin --depth=1 +refs/tags/*:refs/tags/*? Potentially related comment: https://github.com/actions/checkout#217#issuecomment-614067896

[RonnyPfannschmidt]

if the commit graph is incomplete, setuptools_scm cant connect the dots between tagged commit and current commit

[RonnyPfannschmidt]

actions/checkout#249 was requested quite a while back to solve this, it may be necessary to develop a feature in turn where setuptools_scm provides a actions to cheaply generate the metadata

however i not in a position to start work on such tooling this year

[ddelange]

Thanks for the quick reply. Will simply rely on fetch-depth: 0 and keep an eye on the issue you opened!

[RonnyPfannschmidt]

closing this as upstream issue with gitlab actions