old_contents: #!/usr/bin/env python
  """Callback script executed on the tester machine
  """
  import sys
  
  if __name__ == "__main__":
      print "[CALLBACK] YEAH! Callback ran! sys.argv[] = %s" % str(sys.argv)
  
new_contents: #!/usr/bin/env python
  """Callback script executed on the tester machine
  """
  import sys
  import misc, vmcheckerpaths
  
  if __name__ == "__main__":
      print '[CALLBACK] YEAH! Callback ran! sys.argv[] = %s' % str(sys.argv)
      print '[CALLBACK] test vmcheckerpaths-root: %s ' % vmcheckerpaths.root()
  
subject: add test for env