Traceback (most recent call last):
  File "/usr/bin/pycentral", line 1674, in <module>
    main()
  File "/usr/bin/pycentral", line 1668, in main
    rv = action.run(global_options)
  File "/usr/bin/pycentral", line 1169, in run
    pkg.prepare(used_runtimes, old_used_runtimes, old_pkg)
  File "/usr/bin/pycentral", line 793, in prepare
    self.default_runtime.remove_byte_code(removed_fs)
AttributeError: 'NoneType' object has no attribute 'remove_byte_code'