IT notes

OBJC_DISABLE_INITIALIZE_FORK_SAFETY

In macOS High Sierra if getting this: objc[55492]: +[__NSPlaceholderDate initialize] may have been in progress in another thread when fork() was called. objc[55492]: +[__NSPlaceholderDate 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. Define: export OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES This will fix temporally fix the problem and allow program to continue executing, more about this issue here: http://sealiesoftware.

forkbomb

forkbomb C example: #include <stdio.h> int main() { while(1) fork(); } To compile: $ clang bomg.c Python example: import os while True: os.fork() How to prevent it, use RCTL for example in a jail: $ rctl -a jail:myJail:maxproc:deny=50