reference:src.fedoraproject.org/rpms/cdrkit/blob/rawhide/f/cdrkit-1.1.11-gcc10.patch
diff -up cdrkit-1.1.11/genisoimage/genisoimage.h.me cdrkit-1.1.11/genisoimage/genisoimage.h
--- cdrkit-1.1.11/genisoimage/genisoimage.h.me	2020-02-24 15:10:35.542998992 +0100
+++ cdrkit-1.1.11/genisoimage/genisoimage.h	2020-02-24 15:10:50.011130450 +0100
@@ -377,7 +377,7 @@ extern int	use_fileversion;
 extern int	split_SL_component;
 extern int	split_SL_field;
 extern char	*trans_tbl;
-char		*outfile;
+extern char	*outfile;
 
 #define	JMAX		64	/* maximum Joliet file name length (spec) */
 #define	JLONGMAX	103	/* out of spec Joliet file name length */
