docs: def setup_freesurfer():
      '''Setup the freesurfer environment variables'''
      guess_home()
      os.environ['FREESURFER_HOME'] = freesurfer_home
      os.environ['SUBJECTS_DIR'] = subjects_dir
      # Run the setup script and collect the output:
      o = subprocess.check_output(['bash','-c','source %s/SetUpFreeSurfer.sh && env' % freesurfer_home])
      env = [(a.partition('=')[0],a.partition('=')[2]) for a in o.split('\n') if len(a.strip())>0]
      for e in env:
          os.environ[e[0]] = e[1]
      environ_setup = True