What needs to be done that this gets merged?
Having to carry an increasingly large patch for NixOS is not ideal for us and it would be preferred if this could get merged.

Ingo, what do you think?

In D545#6031, @bnavigator wrote:

The patch already updates to the current version + the GnuPG specific changes. Make a diff to http://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=blob_plain;f=m4/ax_python_devel.m4;hb=df506ec920751087985f322e9b60d263c828661c and see for yourself.
What did you do additionally?

The patch didn't make the necessary change to configure.ac which makes a missing Python a non-fatal warning instead of an error. See https://dev.gnupg.org/rMe3ae88267f03b435ec7d9e80ae1e2891e1f118e6. I had the update of ax_python_devel anyway lying around locally since some time.

After my update of m4/ax_python_devel.m4 I retested the patch, but now the build fails for python 3.10:

I am sorry, I am not too familiar with this development platform. Where do I see your changes and what went wrong?

https://dev.gnupg.org/source/gpgme/history/master/

Using pip 23.3.2 from /usr/lib/python3.10/site-packages/pip (python 3.10)
Defaulting to user installation because normal site-packages is not writeable
ERROR: Directory '../../../../src/gpgme/lang/python' is not installable. Neither 'setup.py' nor 'pyproject.toml' found.

But there *is* a setup.py in lang/python, The .in file is even part of the patch

No, there isn't. There is a setup.py in the build folder, but not in the src folder. I suppose the problem doesn't show on build.opensuse.org because they do in-source builds.

I think this patch needs to keep the old code for older versions of Python and only use the new code for 3.12+.

With this patch applied, the openSUSE package for 1.23.2 builds fine with Python 3.9, 3.10, 3.11: https://build.opensuse.org/package/live_build_log/openSUSE:Factory/gpgme/standard/x86_64
... and with 3.12 in staging: https://build.opensuse.org/package/live_build_log/openSUSE:Factory:Staging:K/gpgme/standard/x86_64 (These logs are not permanently stored)

I'm using openSUSE Tumbleweed locally with Python 2.7, 3.8, 3.9, 3.10 and 3.11 being installed, but only devel packages for 3.8, 3.10 and 3.11. Therefore, AX_PYTHON_DEVEL failed for me for 2.7 and 3.9 with this patch because the "optional" option wasn't set to true. But that's fixed with the above mentioned commit.

So what now? You just updated the m4 files in master yourself and I should remove it here? Way to encourage contributions.

The patch didn't make the necessary change to configure.ac which makes a missing Python a non-fatal warning instead of an error.

I don't understand this. It was fatal before and by default still is. The new serial just adds the optional option.
Edit: Okay the new optional option cleans one of the dropped custom changes to the ax_python_devel.m4, got it.