I\'ve got an app that I\'m trying to get working again after wiping my system and installing Snow Leopard. I installed Ruby 1.9 from Macports (now a later version) and the d
"Illegal instruction" is usually an error message from the CPU meaning some piece of binary code you tried to run contained an instruction that is not implemented on that particular CPU.
This can have multiple reasons:
Got it! Appropriately enough, the error was caused by a stack overflow.