gh-109566: regrtest reexecutes the process

[vstinner]

When --fast-ci or --slow-ci option is used, regrtest now replaces the current process with a new process to add "-u -W default -bb -E" options to Python.

The following methods to run the Python test suite don't replace the process:

• "import test.autotest"
• "from test.regrtest import main; main()"

Changes:

• PCbuild/rt.bat and Tools/scripts/run_tests.py no longer need to add "-u -W default -bb -E" options to Python: it's now done by regrtest.
• Fix Tools/scripts/run_tests.py: flush stdout before replacing the process. Previously, buffered messages were lost.

• Issue: Unify ways to run the Python test suite #109566

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot ARM64 macOS 3.x has failed when building commit fbfec56.

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/all/#builders/725/builds/5749) and take a look at the build logs.
4. Check if the failure is related to this commit (fbfec56) 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/all/#builders/725/builds/5749

Failed tests:

• test.test_concurrent_futures.test_deadlock
• test_mmap

Failed subtests:

• test_access_parameter - test.test_mmap.MmapTests.test_access_parameter

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

==

Click to see traceback logs

Traceback (most recent call last):
  File "/Users/buildbot/buildarea/3.x.pablogsal-macos-m1.macos-with-brew/build/Lib/test/test_mmap.py", line 258, in test_access_parameter
    m = mmap.mmap(f.fileno(), mapsize, prot=prot)
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
PermissionError: [Errno 1] Operation not permitted

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot s390x RHEL8 LTO 3.x has failed when building commit fbfec56.

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/all/#builders/567/builds/4975) and take a look at the build logs.
4. Check if the failure is related to this commit (fbfec56) 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/all/#builders/567/builds/4975

Failed tests:

• test_eintr

Failed subtests:

• test_lockf - main.FNTLEINTRTest.test_lockf
• test_all - test.test_eintr.EINTRTests.test_all

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

==

Click to see traceback logs

Traceback (most recent call last):
  File "/home/dje/cpython-buildarea/3.x.edelsohn-rhel8-z.lto/build/Lib/test/test_eintr.py", line 17, in test_all
    script_helper.run_test_script(script)
  File "/home/dje/cpython-buildarea/3.x.edelsohn-rhel8-z.lto/build/Lib/test/support/script_helper.py", line 300, in run_test_script
    raise AssertionError(f"{name} failed")
AssertionError: script _test_eintr.py failed


Traceback (most recent call last):
  File "/home/dje/cpython-buildarea/3.x.edelsohn-rhel8-z.lto/build/Lib/test/_test_eintr.py", line 523, in test_lockf
    self._lock(fcntl.lockf, "lockf")
  File "/home/dje/cpython-buildarea/3.x.edelsohn-rhel8-z.lto/build/Lib/test/_test_eintr.py", line 515, in _lock
    self.assertGreaterEqual(dt, self.sleep_time)
AssertionError: 0.19994455599226058 not greater than or equal to 0.2

[hugovk]

Looks like this PR has stopped a lot of the Windows tests from running.

---

The merge to main before this one:

Windows (x86): 16m 44s

...
425 tests OK.

Total duration: 16 min 42 sec
Total tests: run=38,802 skipped=2,286
Total test files: run=461/463 skipped=36 resource_denied=2
Result: SUCCESS

Windows (x64): 21m 14s

...
425 tests OK.

Total duration: 21 min 12 sec
Total tests: run=38,803 skipped=2,305
Total test files: run=461/463 skipped=36 resource_denied=2
Result: SUCCESS

https://github.com/python/cpython/actions/runs/6315907067

---

This PR's merge to main:

Windows (x86): 7s

...
0:00:00 Run 463 tests in parallel using 4 worker processes (timeout: 10 min, worker timeout: 15 min)
0:00:01 [  1/463] test_xml_dom_minicompat passed
0:00:01 [  2/463] test__opcode passed
0:00:01 [  3/463] test_isinstance passed
0:00:03 [  4/463] test.test_multiprocessing_forkserver.test_threads skipped
test.test_multiprocessing_forkserver.test_threads skipped -- forkserver is not available on Windows

Windows (x64): 7s

...
0:00:00 Run 463 tests in parallel using 4 worker processes (timeout: 10 min, worker timeout: 15 min)
0:00:01 [  1/463] test_frozen passed
0:00:02 [  2/463] test_netrc passed

https://github.com/python/cpython/actions/runs/6317024686

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot ARM Raspbian 3.x has failed when building commit fbfec56.

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/all/#builders/424/builds/5017) and take a look at the build logs.
4. Check if the failure is related to this commit (fbfec56) 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/all/#builders/424/builds/5017

Failed tests:

• test.test_concurrent_futures.test_wait

Failed subtests:

• test_timeout - test.test_concurrent_futures.test_wait.ProcessPoolForkserverWaitTest.test_timeout

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

==

Click to see traceback logs

Traceback (most recent call last):
  File "/var/lib/buildbot/workers/3.x.gps-raspbian.nondebug/build/Lib/test/test_concurrent_futures/test_wait.py", line 128, in test_timeout
    self.assertEqual(set([CANCELLED_AND_NOTIFIED_FUTURE,
AssertionError: Items in the first set but not the second:
<Future at 0xf621ef30 state=running>