anchor.diff:  (defun sbcl-clean (argv)
     (format t "~&Cleaning~%")
     (let ((src (get-opt "src")))
  -    (uiop/os:chdir src)
  -    (format t "~&chdir ~A~%" src)
  +    (ros.util:chdir src)
       (let* ((out (make-broadcast-stream))
              (*standard-output* (make-broadcast-stream
                                  out #+sbcl(make-instance 'count-line-stream))))
  
positive.code:         (uri "https://gist.githubusercontent.com/snmsts/e8e4fd4bd5e458ac45e8/raw/bb7f1cd2e8e9a914f4e9b1b5acf889ecf75dfe0c/posix-tests.patch"))
      (format t "~&Downloading patch: ~A~%" uri)
      (download uri file)
      (uiop/os:chdir (get-opt "src"))
      (format t "~&chdir ~A~%" (get-opt "src"))
      (format t "~%Applying patch:~%")
      (uiop/run-program:run-program "patch -p0 -N" :output t :input file :ignore-error-status t))
    (cons t argv))
  
negative.code:       (format t "~&prefix: ~s~%" impl-path)
        (ensure-directories-exist impl-path)
        (ensure-directories-exist log-path)
        (ros.util:chdir src)
        (ros:unsetenv "SBCL_HOME")
        (ros:setenv "INSTALL_ROOT" (format nil "~A" install-root))
        (with-open-file (out log-path :direction :output :if-exists :append :if-does-not-exist :create)
  