[fine] Test for function return type mismatch

fine/src/semantics.rs

@@ -664,11 +664,6 @@ impl<'a> Semantics<'a> {
 
         // NOTE: These return `None` if they encounter some problem.
         let result = result.unwrap_or(Type::Error);
-
-        if result.is_error() {
-            eprintln!("OH NO AN ERROR AT {}: {:?}", t.index(), tree);
-        }
-
         self.types.borrow_mut()[t.index()] = Incremental::Complete(result.clone());
         result
     }