ISO C99 requires <errno.h>.
Many files in the project already include <errno.h> unconditionally,
so it's reasonable to assume that it is always available.
Link: <https://github.com/shadow-maint/shadow/pull/600>
Cc: Christian Göttsche <cgzones@googlemail.com>
Cc: Iker Pedrosa <ipedrosa@redhat.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
dnl Checks for libraries.
dnl Checks for header files.
-AC_CHECK_HEADERS(crypt.h errno.h fcntl.h limits.h unistd.h sys/time.h utmp.h \
+AC_CHECK_HEADERS(crypt.h fcntl.h limits.h unistd.h sys/time.h utmp.h \
utmpx.h termios.h termio.h sgtty.h sys/ioctl.h syslog.h paths.h \
utime.h ulimit.h sys/capability.h sys/random.h sys/resource.h \
gshadow.h lastlog.h locale.h rpc/key_prot.h netdb.h acl/libacl.h \
#include <stdlib.h>
#include <string.h>
-#if HAVE_ERRNO_H
-# include <errno.h>
-#endif
+#include <errno.h>
#include <sys/stat.h>
#include <sys/types.h>