gh-127146: Emscripten Include compiler version in _PYTHON_HOST_PLATFORM

[hoodmane]

test_sysconfigdata_json is failing. This doesn't entirely fix it but it moves the failure later -- before this change it doesn't even find the sysconfigdata file because of a descrepancy between what uname() returns and what configure.ac sets _PYTHON_HOST_PLATFORM to. After, there are some small differences.

• Issue: Emscripten: Get test suite passing #127146

[hoodmane]

To actually fix the test, we could either skip the check for prefix-related keys or regenerate the sysconfigdata with the cli after the build is completed. The first change would look like:

@@ -651,9 +652,13 @@ def test_sysconfigdata_json(self):
         system_config_vars = get_config_vars()
 
         # Ignore keys in the check
-        for key in ('projectbase', 'srcdir'):
-            json_config_vars.pop(key)
-            system_config_vars.pop(key)
+        ignore_keys = ('projectbase', 'srcdir')
+        if is_emscripten:
+            ignore_keys += ("exec_prefix", "installed_base", "installed_platbase", "prefix", "platbase", "userbase")
+
+        for key in ignore_keys:
+            json_config_vars.pop(key, None)
+            system_config_vars.pop(key, None)
 
         self.assertEqual(system_config_vars, json_config_vars)

@freakboy3742 maybe we could do this for android and ios too?

[freakboy3742]

The change itself makes sense; one note inline about formatting, and it looks like CI is failing because autoreconf hasn't been run since your most recent update.

[bedevere-app]

A Python core developer has requested some changes be made to your pull request before we can consider merging it. If you could please address their requests along with any other requests in other reviews from core developers that would be appreciated.

Once you have made the requested changes, please leave a comment on this pull request containing the phrase I have made the requested changes; please review again. I will then notify any core developers who have left a review that you're ready for them to take another look at this pull request.

[hoodmane]

I have made the requested changes; please review again

[bedevere-app]

Thanks for making the requested changes!

@freakboy3742: please review the changes made to this pull request.

[freakboy3742]

Thanks for those fixes - looks great!

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot AMD64 Windows Server 2022 NoGIL 3.x has failed when building commit b92f101.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/#/builders/1241/builds/4076) and take a look at the build logs.
4. Check if the failure is related to this commit (b92f101) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/#/builders/1241/builds/4076

Failed tests:

• test_venv

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
  File "C:\Users\Administrator\buildarea\3.x.itamaro-win64-srv-22-aws.x64.nogil\build\Lib\test\test_venv.py", line 615, in test_multiprocessing
    out, err = check_output([self.envpy(real_env_dir=True), '-c',
               ~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        'from multiprocessing import Pool; '
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        'pool = Pool(1); '
        ^^^^^^^^^^^^^^^^^^
        'print(pool.apply_async("Python".lower).get(3)); '
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        'pool.terminate()'])
        ^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Administrator\buildarea\3.x.itamaro-win64-srv-22-aws.x64.nogil\build\Lib\test\test_venv.py", line 58, in check_output
    raise subprocess.CalledProcessError(
        p.returncode, cmd, out, err)
subprocess.CalledProcessError: Command '['C:\\Users\\Administrator\\AppData\\Local\\Temp\\test_python_sfi65_yv\\tmpjhxztw7a\\Scripts\\python3.14t_d.exe', '-c', 'from multiprocessing import Pool; pool = Pool(1); print(pool.apply_async("Python".lower).get(3)); pool.terminate()']' returned non-zero exit status 1.


Traceback (most recent call last):
  File "C:\Users\Administrator\buildarea\3.x.itamaro-win64-srv-22-aws.x64.nogil\build\Lib\test\test_venv.py", line 615, in test_multiprocessing
    out, err = check_output([self.envpy(real_env_dir=True), '-c',
               ~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        'from multiprocessing import Pool; '
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        'pool = Pool(1); '
        ^^^^^^^^^^^^^^^^^^
        'print(pool.apply_async("Python".lower).get(3)); '
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        'pool.terminate()'])
        ^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Administrator\buildarea\3.x.itamaro-win64-srv-22-aws.x64.nogil\build\Lib\test\test_venv.py", line 58, in check_output
    raise subprocess.CalledProcessError(
        p.returncode, cmd, out, err)
subprocess.CalledProcessError: Command '['C:\\Users\\Administrator\\AppData\\Local\\Temp\\test_python_juj1et4h\\tmp36bh_36p\\Scripts\\python3.14t_d.exe', '-c', 'from multiprocessing import Pool; pool = Pool(1); print(pool.apply_async("Python".lower).get(3)); pool.terminate()']' returned non-zero exit status 1.


Traceback (most recent call last):

[freakboy3742]

I can't see why this change would have any impact on Windows being unable to start multiprocessing...

[hoodmane]

Presumably a flake =)