the whole expression must be state, not just the anonymous variable

Author: gfldex

doc/Language/typesystem.pod6

@@ -607,6 +607,6 @@ X<|dynamic subset>
 
 =for code :skip-test
 require ::('YourModule');
-subset C where $ = ::('YourModule::C');
+subset C where state $ = ::('YourModule::C');
 
 =end pod