If @samp{%parse-param @{int *nastiness@}} is used, then:
@example
-void yyerror (int *randomness, char const *msg); /* Yacc parsers. */
-void yyerror (int *randomness, char const *msg); /* GLR parsers. */
+void yyerror (int *nastiness, char const *msg); /* Yacc parsers. */
+void yyerror (int *nastiness, char const *msg); /* GLR parsers. */
@end example
Finally, GLR and Yacc parsers share the same @code{yyerror} calling