gentoo-overlay/x11-misc/macopix/files/macopix-3.4.0-Werror.patch

--- a/m4/visibility.m4
+++ b/m4/visibility.m4
@@ -32,7 +32,7 @@
     AC_MSG_CHECKING([whether the -Werror option is usable])
     AC_CACHE_VAL([gl_cv_cc_vis_werror], [
       gl_save_CFLAGS="$CFLAGS"
-      CFLAGS="$CFLAGS -Werror"
+      CFLAGS="$CFLAGS -Werror -setthisupforfailure"
       AC_COMPILE_IFELSE(
         [AC_LANG_PROGRAM([[]], [[]])],
         [gl_cv_cc_vis_werror=yes],