Python fails to locate system version of ffi when building. We delete bundled version of ffi and build process fail with following error: error: [Errno 2] No such file or directory: '/builddir/build/BUILD/Python-3.5.1/Modules/_ctypes/libffi' This is caused by setup.py@1993 checking only for '#define LIBFFI_H' within ffi.h. Content of /usr/include/ffi.h: > $ cat /usr/include/ffi.h /* This file is here to prevent a file conflict on multiarch systems. */ #ifdef ffi_wrapper_h #error "Do not define ffi_wrapper_h!" #endif #define ffi_wrapper_h #if defined(__i386__) #include "ffi-i386.h" #elif defined(__powerpc64__) #include "ffi-ppc64.h" #elif defined(__powerpc__) #include "ffi-ppc.h" #elif defined(__s390x__) #include "ffi-s390x.h" #elif defined(__s390__) #include "ffi-s390.h" #elif defined(__x86_64__) #include "ffi-x86_64.h" #else #error "The libffi-devel package is not usable with the architecture." #endif #undef ffi_wrapper_h It is important to note that this content is Fedora specific. As a workaround we (Fedora) use attached patch. Would it be plausible to accept this patch in upstream?