https://github.com/python/cpython/commit/d7befad328ad1a6d1f812be2bf154c1cd1e... commit: d7befad328ad1a6d1f812be2bf154c1cd1e01fbc branch: master author: Victor Stinner <vstinner@redhat.com> committer: GitHub <noreply@github.com> date: 2019-04-25T14:30:16+02:00 summary: bpo-35537: Document posix_spawn() change in subprocess (GH-11668) Document that subprocess.Popen no longer raise an exception on error like missing program on very specific platforms when using os.posix_spawn() is used. files: M Doc/library/subprocess.rst M Doc/whatsnew/3.8.rst diff --git a/Doc/library/subprocess.rst b/Doc/library/subprocess.rst index ca0813c7830a..3280c95cacbb 100644 --- a/Doc/library/subprocess.rst +++ b/Doc/library/subprocess.rst @@ -567,6 +567,13 @@ functions. Popen destructor now emits a :exc:`ResourceWarning` warning if the child process is still running. + .. versionchanged:: 3.8 + Popen can use :func:`os.posix_spawn` in some cases for better + performance. On Windows Subsystem for Linux and QEMU User Emulation, + Popen constructor using :func:`os.posix_spawn` no longer raise an + exception on errors like missing program, but the child process fails + with a non-zero :attr:`~Popen.returncode`. + Exceptions ^^^^^^^^^^ diff --git a/Doc/whatsnew/3.8.rst b/Doc/whatsnew/3.8.rst index ae8163a1b156..344656b9288f 100644 --- a/Doc/whatsnew/3.8.rst +++ b/Doc/whatsnew/3.8.rst @@ -729,6 +729,12 @@ Changes in Python behavior Changes in the Python API ------------------------- +* :class:`subprocess.Popen` can now use :func:`os.posix_spawn` in some cases + for better performance. On Windows Subsystem for Linux and QEMU User + Emulation, Popen constructor using :func:`os.posix_spawn` no longer raise an + exception on errors like missing program, but the child process fails with a + non-zero :attr:`~Popen.returncode`. + * The :meth:`imap.IMAP4.logout` method no longer ignores silently arbitrary exceptions.