Round 'bout 10 years ago I was working on this Python C extension and, after a distro upgrade, it started segfaulting. Dropping down into gdb, python was fairly obviously calling the wrong C function. I didn't know if the linker, compiler or python was at fault and "it is never a compiler error" was at the forefront of my mind so I never even tried to report the incorrect behavior out of fear that maybe I was doing something stupid that caused gcc to compile an incorrect shared library without complaining.

IIRC after the next fedora release everything started working again so maybe not me? Still don't know.