When I tried to upload a patch from Catapult, I encountered this exception:

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maxlg@maxlg0:~/Develop/gitRepo/catapult$ git cl upload
Running presubmit upload checks ...
Traceback (most recent call last):
  File "/usr/local/google/home/maxlg/Tools/depot_tools/git_cl.py", line 6046, in <module>
    sys.exit(main(sys.argv[1:]))
  File "/usr/local/google/home/maxlg/Tools/depot_tools/git_cl.py", line 6028, in main
    return dispatcher.execute(OptionParser(), argv)
  File "/usr/local/google/home/maxlg/Tools/depot_tools/subcommand.py", line 252, in execute
    return command(parser, args[1:])
  File "/usr/local/google/home/maxlg/Tools/depot_tools/git_cl.py", line 5059, in CMDupload
    return cl.CMDUpload(options, args, orig_args)
  File "/usr/local/google/home/maxlg/Tools/depot_tools/git_cl.py", line 1596, in CMDUpload
    change=change, parallel=options.parallel)
  File "/usr/local/google/home/maxlg/Tools/depot_tools/git_cl.py", line 1530, in RunHook
    parallel=parallel)
  File "/usr/local/google/home/maxlg/Tools/depot_tools/presubmit_support.py", line 1546, in DoPresubmitChecks
    results += executer.ExecPresubmitScript(presubmit_script, filename)
  File "/usr/local/google/home/maxlg/Tools/depot_tools/presubmit_support.py", line 1453, in ExecPresubmitScript
    result = eval(function_name + '(*__args)', context)
  File "<string>", line 1, in <module>
  File "<string>", line 126, in CheckChangeOnUpload
  File "<string>", line 109, in CheckChange
  File "/usr/local/google/home/maxlg/Tools/depot_tools/presubmit_canned_checks.py", line 1032, in PanProjectChecks
    input_api, output_api, source_file_filter=None))
  File "/usr/local/google/home/maxlg/Tools/depot_tools/presubmit_canned_checks.py", line 879, in CheckOwners
    approval_needed=input_api.is_committing)
  File "/usr/local/google/home/maxlg/Tools/depot_tools/presubmit_canned_checks.py", line 926, in GetCodereviewOwnerAndReviewers
    owner_email = input_api.gerrit.GetChangeOwner(issue)
AttributeError: 'NoneType' object has no attribute 'GetChangeOwner