gh-98552: flush std streams in the multiprocessing forkserver before fork (#141849)

* flush std streams in the multiprocessing forkserver before fork * NEWS
2025-12-08 06:10:17 +00:00 · 2025-11-22 10:29:51 -08:00 · 2025-11-22 10:29:51 -08:00 · 58badb1711
commit 58badb1711
parent 08477dbf30
2 changed files with 5 additions and 0 deletions
--- a/Lib/multiprocessing/forkserver.py
+++ b/Lib/multiprocessing/forkserver.py
@ -326,6 +326,7 @@ def sigchld_handler(*_unused):
                                    len(fds)))
                        child_r, child_w, *fds = fds
                        s.close()
+                        util._flush_std_streams()
                        pid = os.fork()
                        if pid == 0:
                            # Child