https://sourceforge.net/p/mjpeg/bugs/144/
https://bugs.gentoo.org/899868
--- a/configure.ac
+++ b/configure.ac
@@ -236,7 +236,7 @@ dnl Check to see if __progname is provided by the system
 dnl ********************************************************************
 AC_CACHE_CHECK([for __progname],
                [mjt_cv_extern___progname],
-               [AC_LINK_IFELSE([AC_LANG_PROGRAM([[]],
+               [AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <stdio.h>]],
                                                 [[extern char *__progname;
                                                   puts(__progname);]])],
                                [mjt_cv_extern___progname=yes],