Fall back to distutils for old Pythons: setuptools for Python 2.7 does not have setuptools.command.build.build

In D545#6037, @ikloecker wrote:

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.

Remove the changes for m4/ax_python_devel.m4 serial 36 commit to master in the meantime.

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

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

Wrong button? Didn't mean to abandon

In D545#6028, @ikloecker wrote:

I have updated m4/ax_python_devel.m4 to the current version and changed the call in configure.ac to set optional to true (which this patch didn't do causing the build to fail).

Also remove deprecated setup.py calls, use PEP517 style instead.

forgot the setup.py.in

• After two years, bump from serial 23 to 36
• Remove more distutils usage

I think it's worth noting that this is not restricted to encrypted e-mails but signed-only e-mails also.

The new revision uses the python.m4 version from automake 1.16.5 and keeps Werner's modifications with the 4th parameter.
See also https://dev.gnupg.org/T3354 and https://dev.gnupg.org/rMff6ff616aea6f59b7f2ce1176492850ecdf3851e

I am not sure if you assumption about the intention is correct. After all, the openSUSE rpm build does use it for creating binding packages for all available python3 versions. If you remove the functionality to find all available versions ("flavors" in the openSUSE rpm packager lingo), the RPM build would need to introduce separate calls of configure and make.

Format sys.version_info[:2] instead of cutting it from sys.version[:3]
as Python versions >= 3.10 have more than 3 characters for their version
string. Bump minimum Python version to 2.1 because the new
ax_python_devel specifies this.