This function exists only on Hurd and is therefore
missing on all non-glibc platforms:
glibc/Linux, glibc/kFreeBSD, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.3, AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.