ref: b9c1eab2e63e1c9b38d1c6a7a2170016e7f0a56c 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; }