Barry A. Warsaw <ba...@python.org> added the comment: On Dec 12, 2018, at 17:59, Ned Deily <rep...@bugs.python.org> wrote: > > Ned Deily <n...@python.org> added the comment: > >> Would it be safe to run the multiprocessing tests on recent macOS with the >> OBJC_DISABLE_INITIALIZE_FORK_SAFETY environment variable set? > > See Ronald's reply above in msg331101. I believe his point is that there is > nothing you can do to make this safe. And it's not a new problem with 10.14 > or 10.13. What is new is that Apple is trying to more forcefully make you > aware of the danger by causing the runtime to try to catch and crash these > cases earlier rather than permit them to perhaps silently cause failures > later.
In my experiments at least, setting the env var *does* prevent the crash, but it doesn’t avoid the undefined semantics (i.e. what happens when the ObjC runtime is called at that point?) and I fully expect that Apple will remove that bandaid at some point. The other key thing is that I don’t believe you can set the env var *in process* and have it take effect after the fork. It must be set before the parent process starts. So that probably makes it less useful for the multiprocessing tests by itself. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue33725> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
