diff -ruN bird-2.0.7.orig/nest/route.h bird-2.0.7/nest/route.h
--- bird-2.0.7.orig/nest/route.h	2019-10-16 13:45:52.000000000 +0300
+++ bird-2.0.7/nest/route.h	2020-11-01 02:59:41.199775491 +0200
@@ -458,7 +458,7 @@
 					   protocol-specific metric is availabe */
 
 
-const char * rta_dest_names[RTD_MAX];
+extern const char * rta_dest_names[RTD_MAX];
 
 static inline const char *rta_dest_name(uint n)
 { return (n < RTD_MAX) ? rta_dest_names[n] : "???"; }