objc[28043]: +[__NSCFConstantString initialize] may have been in progress in another thread when fork() was called.

[hiro-v]

Hi there

I found a bug when running with mlchain run on my MBP (OSX 10.15.6 but I suspect this problem can be reproduced on the older versions)

• When configure wrapper: None in mlconfig => Run mlchain run => There is no bug when calling API

• When configure wrapper: gunicorn in mlconfig => Run mlchain run => There is 1 bug that prohibits function called:
  objc[28043]: +[__NSCFConstantString initialize] may have been in progress in another thread when fork() was called. objc[28043]: +[__NSCFConstantString initialize] may have been in progress in another thread when fork() was called. We cannot safely call it or ignore it in the fork() child process. Crashing instead. Set a breakpoint on objc_initializeAfterForkError to debug.

The problem disappears when I run this command before mlchain run
export OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES

As I tested:
On Windows: There is no gunicorn installed. Should find an alternative
On Linux: Everything works fine

[lamhoangtung]

I was unable to reproduce this error on my own machine running MacOS Mojave 10.14.5. Everything else is the same so until we can fix it latter, just use export OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES. Or put it into your .zshrc or .bashrc or .bash_profile to avoid the hassle.

Thanks !