Would it kill glibc to add arc4random?
It's bad enough keeping up with the cruft dreamed up by POSIX; why add BSD functions that nobody uses outside of the BSD microcosm.
Glibc is monolithic; functions that nothing in your system uses are still sitting there in the .so image.
#if !HAVE_ARC4RANDOM
uint32_t arc4random_uniform(uint32_t upper_bound)
{
// ...
}
#endif
to their code? :)