hemlock not starting

Following the instructions at 
<http://www.cons.org/cmucl/hemlock/index.html>, I did (require :clx) and 
(require :hemlock) without problem.  However, when I did (ed) I got this:

* (require :hemlock)

; Loading #p"/usr/lib/cmucl/subsystems/hemlock-library.x86f".
; [GC threshold exceeded with 14,913,976 bytes in use.  Commencing GC.]
; [GC completed with 6,565,512 bytes retained and 8,348,464 bytes freed.]
; [GC will next occur when at least 18,565,512 bytes are in use.]
("HEMLOCK")
* (ed)

There are no digits in this string: ""
   [Condition of type KERNEL:SIMPLE-PARSE-ERROR]

Restarts:
  0: [ABORT] Return to Top-Level.

Debug  (type H for help)

(PARSE-INTEGER "" :START 0 :END ...)
Source:
; File: target:code/reader.lisp
(ERROR 'SIMPLE-PARSE-ERROR
       :FORMAT-CONTROL
       "There are no digits in this string: ~S"
       :FORMAT-ARGUMENTS
       ...)
0]
0

*

;;;; ***************
Just a guess, of course, but it appears (ed) wants a parameter.