> ./configure --prefix=$PWD-build --with-pydebug --quiet
> make -j 4 -s
> git --git-dir ./.git rev-parse --short HEAD
ee171a26c1
> ./python -m sysconfig | grep GIT
GITBRANCH = "git --git-dir ./.git name-rev --name-only HEAD"
GITTAG = "git --git-dir ./.git describe --all --always --dirty"
GITVERSION = "git --git-dir ./.git rev-parse --short HEAD"

Normally, I should get the real values in these variables and not the git commands.
I don't understand why there are the git commands, I don't want to execute the commands, just get the git information.

The result should be
GITBRANCH = "master"
GITTAG = "heads/master"
GITVERSION = "ee171a26c1"

I think there is an issue. Is it right?

Git informations are available as:

>>> sys._git
('CPython', 'heads/fakerepr', 'd353239f83')
>>> sys.version
'3.8.0a0 (heads/fakerepr:d353239f83, Oct 15 2018, 13:20:43) \n[GCC 8.1.1 20180712 (Red Hat 8.1.1-5)]'

sure, but you can also get these info from sysconfig. and for me, there is a problem with sysconfig. two solutions, remove GIT* from sysconfig or fix sysconfig with the right values.

It seems like you misunderstood the purpose of these variables. They are only used to build getbuildinfo which is used to fill sys._git. Depending on the platform and git version, there are different ways to get the version, branch and tag. These variables should not be used to get the Git version, branch and tag: sys._git is here for that. Hum, sadly it's not documented. Or you can parse sys.version.

Victor is correct.  Those GIT* variable are there to communicate between ./configure and the Makefile; they are *not* intended to have actual values for change ids or branch names. Many variables in the Makefile are not intended to be used outside of the build except for those that are explicitly documented or are well-known autoconf variables, like CFLAGS.

While any Git VCS info for the build is captured in sys._git, the _ prefix indicates it is a Python private attribute and thus is not documented.  The documented way to get any VCS info is via the platform module:

$ /usr/local/bin/python3.7
Python 3.7.1rc2 (v3.7.1rc2:6c06ef7dc3, Oct 13 2018, 05:10:29)
[Clang 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import platform
>>> platform.python_branch()
'v3.7.1rc2'
>>> platform.python_revision()
'6c06ef7dc3'
>>> platform.python_build()
('v3.7.1rc2:6c06ef7dc3', 'Oct 13 2018 05:10:29')

https://docs.python.org/3/library/platform.html#platform.python_revision

yep, sure and now, after your explanations (you and victor) I just closed my PR, but to be honnest with your, I was really surprised when I have seen the git commands in the GIT* variables.

Thanks for your review and your time.