gh-146410: Add --pythoninfo option to regrtest

[vstinner]

• Android now runs tests with --pythoninfo to dump build information.
• Add display_title() function.

• Issue: Android/iOS buildbot should run python -m test.pythoninfo #146410

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@freakboy3742 @mhsmith: Does it sound like a reasonable addition to the Android buildbot?

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If this approach is successful on Android, I will propose a similar change for iOS which also lacks python -m test.pythoninfo output.

[freakboy3742]

+1 - definitely seems like a good idea to me, and I agree adding the equivalent to iOS would also make sense (Apple/__main__.py has an analogous test entry point).

[vstinner]

Ok I merged my PR, thanks for the review.

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I will keep an eye on the Android buildbot to see how it goes: https://buildbot.python.org/#/builders/1594.

[vstinner]

Nice! https://buildbot.python.org/#/builders/1594/builds/4361 ran with my change and it works as expected. Extract of test logs:

Python build information
########################

...
build.NDEBUG: ignore assertions (macro defined)
build.Py_DEBUG: No (sys.gettotalrefcount() missing)
builtins.float.double_format: IEEE, little-endian
config[argv]: ('-m', '--slow-ci', '--single-process', '--no-randomize', '--pythoninfo')
config[orig_argv]: ('', '-W', 'error', '-bb', '-E', '-m', 'test', '--slow-ci', '--single-process', '--no-randomize', '--pythoninfo')
...
os.uname: posix.uname_result(sysname='Linux', nodename='localhost', release='5.10.110-android12-9-00004-gb92ac325368e-ab8731800', version='#1 SMP PREEMPT Tue Jun 14 13:40:53 UTC 2022', machine='aarch64')
...
platform.android_ver: AndroidVer(release='12', api_level=32, manufacturer='unknown', model='Android ATD built for arm64', device='emulator64_arm64', is_emulator=True)
platform.architecture: 64bit
platform.platform: Android-12-aarch64-64bit
...
ssl.OPENSSL_VERSION: OpenSSL 3.5.5 27 Jan 2026
...
support.is_android: True
...
sys.getandroidapilevel: 24
sys.platform: android
sys.version: 3.15.0a7+ (heads/main-dirty:b5a27bdcf03, Mar 26 2026, 10:04:01) [Clang 18.0.4 (https://android.googlesource.com/toolchain/llvm-project d8003a456
...
sysconfig[CC]: /Users/android/android-sdk/ndk/27.3.13750724/toolchains/llvm/prebuilt/darwin-x86_64/bin/aarch64-linux-android24-clang
...
sysconfig[HOST_GNU_TYPE]: aarch64-unknown-linux-android
sysconfig[MACHDEP]: android
sysconfig[MULTIARCH]: aarch64-linux-android
...

And I was looking for this information: sys.float_info: sys.float_info(..., iec_60559=False). So the Android platform doesn't define __STDC_IEC_559__ macro.

By the way, I can see that Android is also affected by the issue gh-145410: sys.version is truncated, it doesn't display the full Clang version: 3.15.0a7+ (heads/main-dirty:b5a27bdcf03, Mar 26 2026, 10:04:01) [Clang 18.0.4 (https://android.googlesource.com/toolchain/llvm-project d8003a456.

[mhsmith]

Looks good to me. For future reference, you can also see this in the GitHub Actions run: GHA doesn't support testing Android on aarch64, but works fine on x86_64.

[vstinner]

Looks good to me. For future reference, you can also see this in the GitHub Actions run: GHA doesn't support testing Android on aarch64, but works fine on x86_64.

I noticed that Android on aarch64 doesn't run tests, but I missed the fact that Android on x86_64 runs tests in GHA! That's great!