Bus Error

From Nsnam

A Bus error occurs when ns has performed an illegal operation. It is much like a segmentation fault.

Specifically, it occurs on some platforms (mostly RISC, ie: PowerPC, Sparc, etc) when a non-aligned memory access is attempted. Because compilers are careful about that sort of thing, the most likely cause of the Bus Error is a corrupted pointer, which is a bug. If the bus error is repeatable, debugging with gdb, ddd or another debug should reveal the position of the bug.

Bus errors are often sent to the program as the SIGBUS signal.