anchor.diff:  
   (defun sbcl-help (argv)
     (flet ((fmt (param default more)
  -           (format t "--~A~A ~A~%~5T~A~%" (cond ((eql default t)
  -                                             "without-")
  -                                            ((null default)
  -                                             "with-")
  -                                            (t
  -                                             ""))
  -                   param (or (and (not (null default))
  -                                  (not (eql default t))
  -                                  default)
  -                             "") more)))
  +           (format t "--~A~A ~A~%~5T~A~%"
  +                   (cond ((eql default t) "without-")
  +                         ((null default) "with-")
  +                         (t ""))
  +                   param
  +                   (or (and (not (null default))
  +                            (not (eql default t))
  +                            default)
  +                       "")
  +                   more)))
       (format t "sbcl install options~%")
       (fmt "as" "nickname" "install non-default optioned version of SBCL")
  -    (fmt "thread" t "Build SBCL without support for native threads")
  -    (fmt "core-compression" t "Build SBCL without support for compressed cores and without a dependency on zlib")
  -    (fmt "ldb" nil "Include low-level debugger in the build")
  -    (fmt "xref-for-internals" nil "Include XREF information for SBCL internals (increases core size by 5-6MB)"))
  +    (dolist (e *sbcl-options*)
  +      (apply #'fmt e)))
     (cons t argv))
   
   (setq *install-cmds*
  
positive.code:                       (cond ((position (format nil "--with-~A" opt) (getf argv :argv) :test 'equal) t)
                              ((position (format nil "--without-~A" opt) (getf argv :argv) :test 'equal) nil)
                              (t default)))))
      (with "thread" t)
      (with "core-compression" t)
      (with "ldb" nil)
      (with "xref-for-internals" nil))
    (cons t argv))
  
  (defun sbcl-start (argv)
  
negative.code:       (format nil "~A -l" (merge-pathnames (format nil "impls/~A/~A/~A/~A/msys/1.0/bin/sh" (uname-m) (uname) "msys" "mingw32") (homedir)))
        (which "bash")
        "sh"))
  
  (defvar *sbcl-options*
    '(("thread" t "Build SBCL without support for native threads")
      ("core-compression" t "Build SBCL without support for compressed cores and without a dependency on zlib")
      ("ldb" nil "Include low-level debugger in the build")
      ("xref-for-internals" nil "Include XREF information for SBCL internals (increases core size by 5-6MB)")
      ("simd-pack" nil "Enable SIMD intrinsics")))
  
  (defun sbcl-get-version ()
    (let (result
  