New issue 2808: crypt() not defined in unistd.h breaks build on Fedora 28 https://bitbucket.org/pypy/pypy/issues/2808/crypt-not-defined-in-unistdh-bre... pv: Apparently Fedora (and probably also other systems) are using libxcrypt instead of glibc crypt(). This breaks pypy's crypt module build (translation fails with c compilation error), since crypt() is defined in crypt.h and no longer in unistd.h. https://fedoraproject.org/wiki/Changes/Replace_glibc_libcrypt_with_libxcrypt Not sure how pypy handles system-specific includes, probably just adding `includes=["crypt.h"]` is not the right thing on all systems.