I compiled the just-published snapshot on OS X configured with --enable-gcc-warnings, and saw this:
lib/mgetgroups.c: In function 'mgetgroups':
lib/mgetgroups.c:90:45: error: pointer targets in passing argument 3
of 'getgrouplist' differ in signedness [-Werror=pointer-sign]
ng = getgrouplist (username, gid, g, &max_n_groups);
^
