https://bugs.gentoo.org/711902
--- intercal-0.31-orig/src/perpet.c+++ intercal-0.31/src/perpet.c@@ -85,7 +85,7 @@/* function created by yacc */
extern int yyparse(void);
-int yydebug;+extern int yydebug;/* compilation options */
bool compile_only; /* just compile into C, don't run the linker */