fandango on core: n.

[Unix/C hackers, from the Iberian dance] In C, a wild pointer that runs out of bounds, causing a core dump, or corrupts the malloc(3) arena in such a way as to cause mysterious failures later on, is sometimes said to have ‘done a fandango on core’. On low-end personal machines without an MMU (or Windows boxes, which have an MMU but use it incompetently), this can corrupt the OS itself, causing massive lossage. Other frenetic dances, such as the cha-cha or the watusi, may be substituted. See aliasing bug, precedence lossage, smash the stack, memory leak, memory smash, overrun screw, core.