Cygwin has had an xlocale.h header file for about two and a half years now. It was introduced while getting better glibc compatibility, however glibc has since dropped said header, which by itself seems to be a BSDism AFAICT. It was always a strict subset of the normal locale.h (in fact locale.h includes it) on Cygwin. This header will go away again soon, following the glibc removal and to address several reports of it shadowing XLocale.h from X11 in certain situations (most filesystems on Windows are case insensitive). Perl Configure checks for xlocale.h first and will include it in config.h and perl.h even though it doesn't provide any extra API that Perl would need, then later finds locale.h and includes that, too. I can defeat it via the hints file, but I think that this search strategy is wrong, except maybe on BSD* systems. If locale.h provides all API and xlocale.h doesn#t add any, then it should not be included by default. Regards, Achim. -- +<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+ Wavetables for the Waldorf Blofeld: http://Synth.Stromeko.net/Downloads.html#BlofeldUserWavetables