Mar 23, 2026 · Mar 23, 2026
diff --git a/Lib/test/libregrtest/utils.py b/Lib/test/libregrtest/utils.py
                        f"unexpectedly returned {tmp_dir!r} on WASI"
                    )
                tmp_dir = os.path.join(tmp_dir, 'build')

                # When get_temp_dir() is called in a worker process,
                # get_temp_dir() path is different than in the parent process
                # which is not a WASI process. So the parent does not create
                # the same "tmp_dir" than the test worker process.
                os.makedirs(tmp_dir, exist_ok=True)
        else:
            tmp_dir = tempfile.gettempdir()

diff --git a/Lib/test/libregrtest/worker.py b/Lib/test/libregrtest/worker.py
 worker_json=sys.argv[1]

 tmp_dir=get_temp_dir()
 # get_temp_dir() can be different in the worker and the parent process.
 # For example, if --tempdir option is used.
 os.makedirs(tmp_dir,exist_ok=True)
 work_dir=get_work_dir(tmp_dir,worker=True)

 withexit_timeout():
diff --git a/Misc/NEWS.d/next/Tests/2026-03-24-00-15-58.gh-issue-146202.LgH6Bj.rst b/Misc/NEWS.d/next/Tests/2026-03-24-00-15-58.gh-issue-146202.LgH6Bj.rst
 Fix a race condition in regrtest: make sure that the temporary directory is
 created in the worker process. Previously, temp_cwd() could fail on Windows if
 the "build" directory was not created.  Patch by Victor Stinner.
Original file line number	Diff line number	Diff line change
Expand Up		@@ -452,12 +452,6 @@ def get_temp_dir(tmp_dir: StrPath \| None = None) -> StrPath:
		f"unexpectedly returned {tmp_dir!r} on WASI"
		)
		tmp_dir = os.path.join(tmp_dir, 'build')

		# When get_temp_dir() is called in a worker process,
		# get_temp_dir() path is different than in the parent process
		# which is not a WASI process. So the parent does not create
		# the same "tmp_dir" than the test worker process.
		os.makedirs(tmp_dir, exist_ok=True)
		else:
		tmp_dir = tempfile.gettempdir()

Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -127,6 +127,9 @@ def main() -> NoReturn:
		worker_json=sys.argv[1]

		tmp_dir=get_temp_dir()
		# get_temp_dir() can be different in the worker and the parent process.
		# For example, if --tempdir option is used.
		os.makedirs(tmp_dir,exist_ok=True)
		work_dir=get_work_dir(tmp_dir,worker=True)

		withexit_timeout():
Expand Down
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,3 @@
		Fix a race condition in regrtest: make sure that the temporary directory is
		created in the worker process. Previously, temp_cwd() could fail on Windows if
		the "build" directory was not created. Patch by Victor Stinner.