Fix macOS PHP NSCFConstantString Fork Error with One Env Var

Originally published at recca0120.github.io

When using Guzzle Client in artisan tinker, macOS throws objc[86150]: +[__NSCFConstantString initialize] may have been in progress in another thread when fork() was called. This is caused by the Objective-C runtime's safety check during fork.

Disable the Fork Safety Check

Set an environment variable to skip the check:

export OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES

Add it to ~/.bashrc or ~/.zshrc so you don't have to set it manually every time.