anchor.diff:        (labels
             ((compatible-p (command)
                (sequence-starts-with-p command (simple-word-text token))))
  -        (eager-map (eager-filter (all-binary-commands) #'compatible-p (fset:empty-seq))
  +        (eager-map (eager-filter (all-commands) #'compatible-p (fset:empty-seq))
                      (lambda (str)
                        (make-simple-completion-suggestion str context))
                      (fset:empty-seq))))))
  
positive.code:   (:import-from :shcl/core/fd-table
     #:receive-ref-counted-fd #:retained-fd-openat #:fd-wrapper-value
     #:with-dir-ptr-for-fd)
    (:import-from :shcl/core/posix
     #:fstat #:faccessat #:syscall-error #:do-directory-contents)
    (:import-from :shcl/core/posix-types #:o-rdonly #:st-mode #:x-ok #:at-eaccess)
  
negative.code:     (return-from parse-simple-command-word
        (call-next-method)))
  
    (assert (parser-var +parsed-simple-command-words+))
    (let ((return-values (multiple-value-list (call-next-method))))
      (attachf (parser-var +parsed-simple-command-words+) (car return-values))
      (values-list return-values)))
  
  (defgeneric parse-error-involves-sigil-token-p (err sigil-token))
  