Cygwin

ELIBC setting for systems that use Cygwin

Darwin

ELIBC setting for systems that use the Darwin C library

SunOS

ELIBC setting for systems that use the Sun Solaris C library

Winnt

ELIBC setting for systems that use Winnt

bionic

ELIBC setting for systems that use Android's Bionic C library

glibc

ELIBC setting for systems that use the GNU C library

mingw

ELIBC setting for systems that use the Minimalist GNU for Windows library

musl

ELIBC setting for systems that use the musl C library