The function at issue being initgroups() from the <grp.h> header
file. On Cygwin, setting _XOPEN_SOURCE suppresses the definition
of initgroups(), which causes the warning while compiling daemon.c.
Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk> Signed-off-by: Junio C Hamano <junkio@cox.net>