ref: d159e8c6b102a1c5d9a7625ecc8176f08290c259
dir: /lib/std/errno+plan9.myr/
pkg std = type errno = int const Enone : errno = 0 const Erange : errno = 1 const Ebadf : errno = 2 const Eexist : errno = 3 const Einval : errno = 4 const Efault : errno = 5 const Eio : errno = 6 const Emisc : errno = 40 ;;