Ned Deily: "I don't think we should be adding this platform-version-specific code unless we are going to fully support that particular platform and version."

I know the theory and I know the practice :-)

I started to list platforms that are "supported" by Python, with various support levels:
http://vstinner.readthedocs.io/cpython.html#supported-platforms

For example, Linux has an excellent support, whereas OpenBSD is more on the "best effort" side. "grep OpenBSD" in CPython shows me at least 51 lines of code, whereas OpenBSD has no buildbot and no dedicated developer to handle OpenBSD specific issues. For example, test_crypt is broken since at least 2 years on OpenBSD, as many test_socket tests.

For OpenBSD, IMHO it's ok to have a best effort support, basically apply proposed patches.

For Android, the situation is somehow different. There are more and more people working on supporting officially Python on Android, like Xavier de Gaye and me who are core developers. Xavier is working on that for 2 years, and IMHO the port is done at 95%. The last part is just to setup a buildbot for Android API 24.

The question is the added maintenance cost of Android API 19 #ifdef code, compared to pain of building Python on Android.

Technically, it should be possible to setup a buildbot for Android API 19, but only with a subset of tests. Either explicitly only run a subset of tests on this hypothetic buildbot, or even modify the Python test suite to skip some tests on Android API 19. While I expect a few patches for fix Python compilation on Android API 19, I do expect a lot of @skipIf() in tests, since API 19 has many broken or missing features. The thing is that most people don't care of these missing or broken features, it's not an issue for most applications on Android.

Note: Kivy is using Python on Android for years, but they use CrystaX NDK and not Google NDK. This issue is about supporting Google NDK: have the maximum compatibility.