Fix sourceVersion for 4 element versions (like 2.7.18.9)

[ktosiek]

It turns out my previous PR #49 was incomplete: it fixed building something, but it also broke building the ssl module for 2.7.18.8+.

This time I've added a test that checks if the ssl module is available. So far the test only runs for Python 2.7.18.*, other versions still have problems with building this module.

[domenkozar]

Seems that arm is failing, can you take a look?

[ktosiek]

I'll see what I can do about the ARM64 on Linux build.

So far I see that:

1. on 67b3596 the build of 3.3.1 works (even if ssl is missing)
2. derivation for 3.3.1 in this PR is the same as on main

Currently I believe the problem was introduced with merge of #42 (upgrade to nixos-24.05).

I don't have an arm64 handy, and testing with qemu-binfmt takes ages. Do you know any cheap ($5-10) VM providers that work well for compilation?

[ktosiek]

Failures on aarch64-linux are:

• 3.3: 3.3.1-3.3.6
• 3.4: 3.4.0, 3.4.1

For 3.4: It looks like Python 3.4.x only added support for AArch64 in 3.4.2:
"bpo-22176: Update the ctypes module’s libffi to v3.1. This release adds support for the Linux AArch64 and POWERPC ELF ABIv2 little endian architectures." (https://docs.python.org/3.4/whatsnew/changelog.html#id34)

Would it make sense to exclude building 3.4.0 and 3.4.1 on aarch64? (Edit: 3.4.1 does build on arm on nixos-23.05 somehow)

I still haven't looked at 3.3.

[ktosiek]

I'm out for now, you can find today's findings below. I'll probably try something next week, but I would like to talk to you about directions (should I write an email?).

I did a bisect for 3.4.1 over nixpkgs for this problem ("KeyError: 'AARCH64'"), and it suggests that 97625d0307db3db59b09f4122717cdaed7adc926 is the first bad commit. The commit is titled "cpython: prune patches and configure flags", so it sounds like a plausible suspect.

For the record: I've used one Google Cloud's T2A (spot, it's like 5x cheaper) instance with 8 vCPUs as a builder. It works well. They have a generous free tier, but it's restricted to 90 days from registration.