Debugger misses some variables

[Helmut Eller]

Evaluating code like this:

(progn
  (defun foo (x)
    (flet ((bar () (break "x=~s" x) (print x)))
      #'bar))
  (compile 'foo)
  (funcall (foo '(1 2 3))))

brings up the debugger:

x=(1 2 3)
   [Condition of type simple-condition]

Restarts:
  0: [continue] Return from BREAK.
  1: [abort   ] Return to Top-Level.

But list-locals doesn't show anything:

0] list-locals
All variables currently have invalid values.
0] 

That's odd, since at that point the variable x is still needed by print and so the debugger should be able to display it.