https://bugs.gentoo.org/707310
--- a/PKININIT.c
+++ b/PKININIT.c
@@ -65,6 +65,8 @@ void writeversiontooutput(void); /*041011*/
 void writechangestooutput(void); /*040215*/
 void writecmdhelptooutput(void); /*040425*/
 
+extern int Lribbonnew;
+
 static char* prekinchanges[] =
 {"\r"
 ,"020514 Cbeta:Superpos,NB:Prekin,IOmage\r"
--- a/PKINRIBB.c
+++ b/PKINRIBB.c
@@ -6,6 +6,8 @@
 #define   PKINRIBB
 #include "PKINRIBB.h"
 #undef    PKINRIBB
+
+extern int Lribbonnew;
  
 /*{{{--NOTE--  version, etc. */
 /*051025  for now, just work with one model, and let prekin's levels==sections*/
--- a/PKINRIBB.h
+++ b/PKINRIBB.h
@@ -5,7 +5,7 @@
 #define PKINRIBB extern
 #endif
 
-PKINRIBB    int   Lribbonnew;  /*051025 new ribbon structures: PKINRIBB*/
+extern int   Lribbonnew;  /*051025 new ribbon structures: PKINRIBB*/
 
 #define CORDER 4  /*order of the B-spline defined here*/