ref: f5bbb69877c377e1ff5e4a8cf1bfb3fc8e39b85a 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; }