diff -up kbd-2.2.0/src/libkeymap/analyze.l.orig kbd-2.2.0/src/libkeymap/analyze.l
--- kbd-2.2.0/src/libkeymap/analyze.l.orig	2019-06-25 11:41:55.000000000 +0200
+++ kbd-2.2.0/src/libkeymap/analyze.l	2019-10-17 08:39:01.924605478 +0200
@@ -463,7 +463,10 @@ To                      to|To|TO
 
 					strerror_r(errno, buf, sizeof(buf));
 
+					/* workaround -Werror=format-security error
 					ERR(yyextra, buf);
+					*/
+					ERR(yyextra, _("unknown error"));
 					return(ERROR);
 				}
 
