"xv" 3.10a produces  a fatal error when compiled using new versions of
"gcc" and "glibc". This patch corrects the problem.

--- xv-3.10a.orig/xv.h
+++ xv-3.10a/xv.h
@@ -116,7 +116,9 @@
 #  include <errno.h>
    extern int   errno;             /* SHOULD be in errno.h, but often isn't */
 #  ifndef __NetBSD__
+#ifndef linux
      extern char *sys_errlist[];     /* this too... */
+#endif
 #  endif
 #endif