AC_CACHE_CHECK([whether open can visit directories],
[gl_cv_func_open_directory_works],
[AC_RUN_IFELSE([AC_LANG_PROGRAM([[#include <fcntl.h>
AC_CACHE_CHECK([whether open can visit directories],
[gl_cv_func_open_directory_works],
[AC_RUN_IFELSE([AC_LANG_PROGRAM([[#include <fcntl.h>