message: Improves note about expected warnings from 'spack mirror'
  The note is now before calling 'spack mirror' with
  a second note to indicate when to stop expecting warnings.
diff: @@ -257,10 +257,13 @@ def uberenv_create_mirror(prefix, project_file, mirror_path):
  cmd = "python scripts/uberenv/uberenv.py --create-mirror"
  cmd += " --prefix=\"{0}\" --mirror=\"{1}\"".format(prefix, mirror_path)
  cmd += " --project-json=\"{0}\" ".format(project_file)
  - res = sexe(cmd, echo=True, error_prefix="WARNING:")
  print "[~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~]"
  print "[ It is expected for 'spack --create-mirror' to throw warnings. ]"
  print "[~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~]"
  + res = sexe(cmd, echo=True, error_prefix="WARNING:")
  + print "[~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~]"
  + print "[ End of expected warnings from 'spack --create-mirror' ]"
  + print "[~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~]"
  set_axom_group_and_perms(mirror_path)
  return res
  