__THE_PROCESS_HAS_FORKED_AND_YOU_CANNOT_USE_THIS_COREFOUNDATION_FUNCTIONALITY___YOU_MUST_EXEC__()

[camierjs]

I'm hitting this issue on macOS Catalina 10.15.7:

The process has forked and you cannot use this CoreFoundation functionality safely. You MUST exec().
Break on __THE_PROCESS_HAS_FORKED_AND_YOU_CANNOT_USE_THIS_COREFOUNDATION_FUNCTIONALITY___YOU_MUST_EXEC__() to debug

Has anyone seen/hit this before?
This shows up after adding export OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES in the shell to avoid a first
[NSApplication initialize] may have been in progress in another thread when fork() was called. error.

[tzanio]

@kanye-quest and @jandrej can you help with that?

[tzanio]

Quoting from https://glvis.org/options-and-use/#server-mode:

On legacy Mac machines with OS X Leopard, the server needs to be started with

glvis -mac

This is due to the fact that Mac OS X returns an error when fork() is called without an immediate exec(). Note that this option is not necessary on newer versions of OS X.

@camierjs, can you try that? I really hope they haven't reintroduced this issue in the new versions of macOS 😞

[camierjs]

It seems to work better - but I'm still getting hangs with multiple sockets.

Maybe it's related to the glvis-saved.* files?

[camierjs]

Reverted to Command_Line_Tools_for_Xcode_12.2 and Xcode_12.2 runtime libraries w/o better success.

Removing the multi_session mode allows to at least get one window working properly.

[tzanio]

I can't reproduce this and most Google searches (e.g. "catalina corefoundation fork exec") return result related to Python.

Is it possible that you updated other things besides Xcode? Can you confirm that you see this error with simple ./glvis -m ../mfem/data/star.mesh?

[camierjs]

It turns out that the SDL version 2.0.14 introduces this behavior - 2.0.12 works fine.

[tzanio]

@kanye-quest, heads up that we may run into this problem ☝️ when updating SDL2 on Mac

[camierjs]

I've extracted the sdl2.rb that can install the 2.0.12 SDL2 library through brew with brew install ./sdl2.rb

sdl2.rb.txt

[zahurullah123]

@camierjs Thanks for the script, it also sovled my probem.

[tzanio]

This issue will be addressed by the work in #149

[tzanio]

If the #141 (comment) solution doesn't work for you, you can build SDL2 manually, as described in https://github.com/GLVis/glvis/blob/master/INSTALL#L209-L223.

Here, for completeness, are the necessary commands (on a Mac, from the directory containing glvis/):

wget "https://www.libsdl.org/release/SDL2-2.0.12.tar.gz"
tar zxf SDL2-2.0.12.tar.gz
cd SDL2-2.0.12
./configure --prefix=`dirname $PWD`/SDL2 --disable-video-x11
make -j
make install
cd ..

[tzanio]

This should be resolved in master as of b513773 (Jul 9th, 2021)