ref: b0a059537147237e868b4a8f07922ae8a349e55c dir: /sys/src/ape/lib/ap/plan9/setuid.c/
#include <sys/types.h> #include <unistd.h> #include <errno.h> /* * BUG: never works */ int setuid(uid_t) { errno = EPERM; return -1; }