anchor.diff:                  (not (eq (car old-value) :readable)))
              (consistency-error
               stream form-as-string
  -            "Unreadable value ~:@_~S ~:@_in source became readable ~:@_~S."
  +            "Unreadable value ~:_~S ~:_in source became readable ~:_~S."
               old-value-value value))
             ((and (not value-readable-p)
                   (not (eq (car old-value) :unreadable)))
              (consistency-error
               stream form-as-string
  -            "Readable value ~:@_~S~:@_ in source became unreadable ~:@_~S."
  +            "Readable value ~:_~S~:_ in source became unreadable ~:_~S."
               old-value-value value))
             ;; At this point we know that both are readable or both are
             ;; unreadable.
  
positive.code:   (:report (lambda (condition stream)
               (let ((on (transcription-error-on condition)))
                 (format stream
                         "~@<Transcription error in ~A~@[ ~:@_at position ~A~].~
                         ~:@_~?~:@_~
                         Form: ~:@_~S~:@>"
                         (if (typep on 'reference)
                             ;; Allow M-. to work in the slime debugger.
  
negative.code:         (cond ((/= (length values) (length old-values))
                 (consistency-error
                  stream form-as-string
                  "Source had ~S return values ~:_while there are actually ~S."
                  (length old-values) (length values)))
                (t
                 (loop for value in values
  