anchor.diff:  
   (5am:test build-33
     (is (ast-stabalizes-p
  -       (varjo.tests::compile-vert () :450
  +       (compile-vert () :450
            (let ((fn (labels ((test ((x :int)) x))
                        #'test)))
              (labels ((foo ((ffn (function (:int) :int)))
  
positive.code: 
  (5am:test build-32
    (signals varjo-conditions:symbol-unidentified
      (varjo.tests::compile-vert () :450
        (labels ((foo ((ffn (function (:int) :int)))
                   (funcall ffn y)))
          (let ((y 10))
  
negative.code: 
  (5am:test build-31
    (signals varjo-conditions:cross-scope-mutate
      (compile-vert () :450
        (let* ((y 10)
               (fn (labels ((test ((x :int)) x))
                     #'test)))
  