anchor.diff:  ;;; Extend ASDF and the CFFI groveller to be MPI aware
   (defpackage #:cl-mpi-asdf-utilities
  -  (:use #:asdf #:cl)
  +  (:use #:asdf #:cl #:uiop)
     (:export #:mpi-stub #:grovel-mpi-file))
   
   (in-package #:cl-mpi-asdf-utilities)
  
positive.code: ;;; use "mpicc" as compiler for all mpi related cffi-grovel files
  (defmethod perform ((op cffi-grovel::process-op)
                      (c grovel-mpi-file))
    (let ((cffi-grovel::*cc* "mpicc"))
      (call-next-method)))
  
  (defun compute-mpi-info ()
  
negative.code:           (if (multiple-value-bind (stdout stderr exit-code)
                    (uiop:run-program cmd :ignore-error-status t
                                          :error-output :string)
                  (declare (ignore stdout stderr))
                  (zerop exit-code))
                (progn
                  (format *standard-output* "; ~A~%" cmd)
  