[3.13] gh-146202: Create tmp_dir in regrtest worker (GH-146347) (#146350)

gh-146202: Create tmp_dir in regrtest worker (GH-146347)

Create tmp_dir in libregrtest.worker since the directory can be
different than the --tempdir directory.
(cherry picked from commit bcff99cb3f3b887a08c4f0ace1279ced38dd9e62)

Co-authored-by: Victor Stinner <vstinner@python.org>

diff --git a/Lib/test/libregrtest/utils.py b/Lib/test/libregrtest/utils.py
index f12cec944fd3bf6d9b13b7485e28feb3975a7d14..c0e8c090670bc331dc59b6d4af6db205ff98372f 100644 (file)
--- a/Lib/test/libregrtest/utils.py
+++ b/Lib/test/libregrtest/utils.py
@@ -466,12 +466,6 @@ 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()
 

diff --git a/Lib/test/libregrtest/worker.py b/Lib/test/libregrtest/worker.py
index e0627c4adc0107e2ea7e7599e66ef93ab0e0edb2..c1c7922ae0c65110cea97791789b698b6b57a583 100644 (file)
--- a/Lib/test/libregrtest/worker.py
+++ b/Lib/test/libregrtest/worker.py
@@ -112,6 +112,9 @@ 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)
 
     with exit_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
new file mode 100644 (file)
index 0000000..ef869fe
--- /dev/null
+++ b/Misc/NEWS.d/next/Tests/2026-03-24-00-15-58.gh-issue-146202.LgH6Bj.rst
@@ -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.