fix: fixpoint

src/eval/mod.rs

@@ -305,6 +305,12 @@ impl Evaluate for ir::LetVar {
     }
 }
 
+impl Evaluate for ir::Cache {
+    fn eval(&self, engine: &mut Engine, env: &mut Env) -> Result<Value> {
+        todo!()
+    }
+}
+
 impl Evaluate for ir::Thunk {
     fn eval(&self, engine: &mut Engine, env: &mut Env) -> Result<Value> {
         Value::Thunk(self.idx).ok()