compiling ucpop

[Roger Kirchner <rkirchne@phobos.mathcs.carleton.edu>]

Can anyone understand why I might get the error

ERROR in function GET-OPERS-TEST-TEMPL in lines 263..275 :
RETURN-FROM block TEST-TEMPL is impossible from here.

when compiling

;;; quickly get those operators in the templates that match a condition
(defun get-opers (condition &aux (ret nil))
  (labels ((test-templ (templ)
             (dolist (e (p-step-add templ) nil)
               (dolist (a (effect-add e))
                 (when (and (eql (car a) (car condition))
                            (or (not (eq (car a) :not))
                                (eql (caadr a) (caadr condition))))
                   (return-from test-templ t))))))
    (dolist (templ *templates* ret)
      (when (test-templ templ)
        (push templ ret)))))


This is in ucpop.lisp from a planning system.  Everything compiles
fine with Allegro on a NeXT.  But I was hoping to use clisp.

The error doesn't occur when I just try to compile this code.  It has
to do with the package environment.  Unfortunately, I don't know how
to get determine the state of packages.


Thanks.
Roger Kirchner