That&#x27;s inaccurate, according to the page you linked to (and to my memory of the incident).<p>gcc 1.17 would invoke nethack (or one of several other similar games, if available) if it saw an unrecogized #pragma directive.<p>According to the C standard, the behavior of a #pragma not followed by STDC is implementation-defined, not undefined -- which means that an implementation is required to document its behavior. (I presume that gcc did so.)<p>gcc did not play launch Nethack in response to undefined behavior in general, or in response to anything other than an unrecognized #pragma directive.