On 2009-12-02 21:35 +0100, Mike Castle wrote: > I guess this boils down to: is this a bug in gcc or a bug in my set up? Probably there is something wrong on your system, because gcc works as expected in your example here: ,---- | % LANG=en_US.UTF-8 gcc -Wall -Werror t.c | cc1: warnings being treated as errors | t.c: In function ‘foo’: | t.c:2: error: implicit declaration of function ‘bar’ `---- Maybe your terminal is not in Unicode mode? Sven