How to dismantle a compiler bomb
I had a famous machine learning professor send me a C program that crashed in init on a 32-bit machine because it allocated a 8GB array...It was particularly strange to set a breakpoint at the beginning of main() with gdb and see the program never got there.  Oddly enough,  he never actually used the 8GB array,  even though he had no problem allocating the array on the POWER workstation he was using.