ref: 2a135fe0251242f5c29e599b289877d9be3d6569 dir: /sys/src/ape/lib/ap/plan9/getgroups.c/
#include <sys/types.h> #include <unistd.h> #include <errno.h> int getgroups(int, gid_t*) { errno = EINVAL; return -1; }