POSIX says that "setting a trap for SIGKILL or SIGSTOP produces undefined results", but for signals it describes SIGKILL as "Kill (cannot be caught or ignored)".
I'm guessing this is some relic from 80s Unix systems where SIGKILL behaved different, or perhaps just an inconsistency/oversight.
I'm guessing this is some relic from 80s Unix systems where SIGKILL behaved different, or perhaps just an inconsistency/oversight.