Filed by sheriff-o-matic@appspot.gserviceaccount.com on behalf of alancutter@chromium.org

gclient runhooks failing on chromium.linux/Linux Tests

Builders failed on: 
- Linux Tests: 
  https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Linux%20Tests



________ running '/b/swarming/w/ir/cache/vpython/998566/bin/python src/third_party/depot_tools/download_from_google_storage.py --no_resume --no_auth --num_threads=4 --bucket chromium-tools-traffic_annotation -d src/tools/traffic_annotation/bin/linux64' in '/b/swarming/w/ir/cache/builder'
Traceback (most recent call last):
  File "/b/swarming/w/ir/kitchen-checkout/depot_tools/metrics.py", line 255, in print_notice_and_exit
    yield
  File "/b/swarming/w/ir/kitchen-checkout/depot_tools/gclient.py", line 3083, in <module>
    sys.exit(main(sys.argv[1:]))
  File "/b/swarming/w/ir/kitchen-checkout/depot_tools/gclient.py", line 3069, in main
    return dispatcher.execute(OptionParser(), argv)
  File "/b/swarming/w/ir/kitchen-checkout/depot_tools/subcommand.py", line 252, in execute
    return command(parser, args[1:])
  File "/b/swarming/w/ir/kitchen-checkout/depot_tools/gclient.py", line 2767, in CMDrunhooks
    return client.RunOnDeps('runhooks', args)
  File "/b/swarming/w/ir/kitchen-checkout/depot_tools/gclient.py", line 1735, in RunOnDeps
    self.RunHooksRecursively(self._options, pm)
  File "/b/swarming/w/ir/kitchen-checkout/depot_tools/gclient.py", line 1047, in RunHooksRecursively
    hook.run()
  File "/b/swarming/w/ir/kitchen-checkout/depot_tools/gclient.py", line 240, in run
    cmd, cwd=self.effective_cwd, always=self._verbose)
  File "/b/swarming/w/ir/kitchen-checkout/depot_tools/gclient_utils.py", line 314, in CheckCallAndFilterAndHeader
    return CheckCallAndFilter(args, **kwargs)
  File "/b/swarming/w/ir/kitchen-checkout/depot_tools/gclient_utils.py", line 525, in CheckCallAndFilter
    **kwargs)
  File "/b/swarming/w/ir/kitchen-checkout/depot_tools/subprocess2.py", line 246, in __init__
    super(Popen, self).__init__(args, **kwargs)
  File "/b/swarming/w/ir/cipd_bin_packages/lib/python2.7/subprocess.py", line 390, in __init__
    errread, errwrite)
  File "/b/swarming/w/ir/cipd_bin_packages/lib/python2.7/subprocess.py", line 1024, in _execute_child
    child_exception = pickle.loads(data)
  File "/b/swarming/w/ir/cipd_bin_packages/lib/python2.7/pickle.py", line 1388, in loads
    return Unpickler(file).load()
  File "/b/swarming/w/ir/cipd_bin_packages/lib/python2.7/pickle.py", line 864, in load
    dispatch[key](self)
  File "/b/swarming/w/ir/cipd_bin_packages/lib/python2.7/pickle.py", line 977, in load_string
    self.append(rep.decode("string-escape"))
LookupError: unknown encoding: string-escape
step returned non-zero exit code: 1