git-archive SHA-256 checksums are changing

[asfimport]

@xhochy since we added the git-archive business, I'm getting non-deterministic SHA256 checksums from the archives on GitHub, e.g.

https://circleci.com/gh/conda-forge/arrow-cpp-feedstock/15

from a prior passing build with the same commit hash and SHA256

https://circleci.com/gh/wesm/arrow-cpp-feedstock/3

I suggest that we drop setuptools_scm_git_archive and revert to manual versioning.

Reporter: Wes McKinney / @wesm

_{Note: This issue was originally created as ARROW-429. Please see the migration documentation for further details.}

[asfimport]

Wes McKinney / @wesm:
The .git_archival.txt file (in the exported archives) has some oddness in it:

cat .git_archival.txt 
ref-names: refs/__gh__/pull/237/rebase, refs/__gh__/pull/234/rebase, refs/__gh__/pull/233/rebase, refs/__gh__/pull/231/rebase, refs/__gh__/pull/226/rebase, refs/__gh__/pull/225/rebase, refs/__gh__/pull/220/rebase

I'm going to prepare a patch reverting ARROW-379 until we can investigate this further

[asfimport]

Uwe Korn / @xhochy:
Ok, this needs some digging into the inner workings of Git's export-subst.
For now I would prefer if we just switch the source of the tarball to https://git-wip-us.apache.org/repos/asf?p=arrow.git;a=snapshot;h=f4737d7faf6daefbfa17c7175187adcde0d711ae;sf=tgz as there aren't those github specific tags (but sadly also no subsitutions)

[asfimport]

Uwe Korn / @xhochy:
Issue resolved by pull request 243
#243

[asfimport]

Uwe Korn / @xhochy:
Made a follow-up story: https://issues.apache.org/jira/browse/ARROW-430