ref: 8efbd243e1934288fe6a57d3f168d370f6c04493 dir: /sys/src/ape/lib/ap/plan9/setgid.c/
#include <sys/types.h> #include <unistd.h> #include <errno.h> /* * BUG: never works */ int setgid(gid_t) { errno = EPERM; return -1; }