From db0b455ff482df68f331411bf22b3e5829398280 Mon Sep 17 00:00:00 2001 From: Christian Heimes Date: Sat, 14 May 2022 20:23:19 +0200 Subject: gh-90473: Fail subprocess early on Emscripten/WASI (GH-92802) --- Lib/subprocess.py | 17 +++++++++++------ .../2022-05-14-11-41-23.gh-issue-90473.kPdOZl.rst | 2 ++ 2 files changed, 13 insertions(+), 6 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2022-05-14-11-41-23.gh-issue-90473.kPdOZl.rst diff --git a/Lib/subprocess.py b/Lib/subprocess.py index 6e61cc2..e10b010 100644 --- a/Lib/subprocess.py +++ b/Lib/subprocess.py @@ -74,6 +74,9 @@ except ModuleNotFoundError: else: _mswindows = True +# wasm32-emscripten and wasm32-wasi do not support processes +_can_fork_exec = sys.platform not in {"emscripten", "wasi"} + if _mswindows: import _winapi from _winapi import (CREATE_NEW_CONSOLE, CREATE_NEW_PROCESS_GROUP, @@ -97,13 +100,10 @@ if _mswindows: "CREATE_NO_WINDOW", "DETACHED_PROCESS", "CREATE_DEFAULT_ERROR_MODE", "CREATE_BREAKAWAY_FROM_JOB"]) else: - if sys.platform in {"emscripten", "wasi"}: - def _fork_exec(*args, **kwargs): - raise OSError( - errno.ENOTSUP, f"{sys.platform} does not support processes." - ) - else: + if _can_fork_exec: from _posixsubprocess import fork_exec as _fork_exec + else: + _fork_exec = None import select import selectors @@ -801,6 +801,11 @@ class Popen: encoding=None, errors=None, text=None, umask=-1, pipesize=-1, process_group=None): """Create new Popen instance.""" + if not _can_fork_exec: + raise OSError( + errno.ENOTSUP, f"{sys.platform} does not support processes." + ) + _cleanup() # Held while anything is calling waitpid before returncode has been # updated to prevent clobbering returncode if wait() or poll() are diff --git a/Misc/NEWS.d/next/Library/2022-05-14-11-41-23.gh-issue-90473.kPdOZl.rst b/Misc/NEWS.d/next/Library/2022-05-14-11-41-23.gh-issue-90473.kPdOZl.rst new file mode 100644 index 0000000..bf5ee54 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2022-05-14-11-41-23.gh-issue-90473.kPdOZl.rst @@ -0,0 +1,2 @@ +:mod:`subprocess` now fails early on Emscripten and WASI platforms to work +around missing :func:`os.pipe` on WASI. -- cgit v0.12