Parsing OWNER files causes a problem. I think it was introduced in https://crrev.com/c/1204917.

PS C:\src\v8> git cl upload
Running presubmit upload checks ...
Traceback (most recent call last):
  File "C:\src\depot_tools\metrics.py", line 255, in print_notice_and_exit
    yield
  File "C:\src\depot_tools\git_cl.py", line 5939, in <module>
    sys.exit(main(sys.argv[1:]))
  File "C:\src\depot_tools\git_cl.py", line 5921, in main
    return dispatcher.execute(OptionParser(), argv)
  File "C:\src\depot_tools\subcommand.py", line 252, in execute
    return command(parser, args[1:])
  File "C:\src\depot_tools\metrics.py", line 240, in _inner
    return self._collect_metrics(func, command_name, *args, **kwargs)
  File "C:\src\depot_tools\metrics.py", line 200, in _collect_metrics
    result = func(*args, **kwargs)
  File "C:\src\depot_tools\git_cl.py", line 4983, in CMDupload
    return cl.CMDUpload(options, args, orig_args)
  File "C:\src\depot_tools\git_cl.py", line 1641, in CMDUpload
    change=change, parallel=options.parallel)
  File "C:\src\depot_tools\git_cl.py", line 1583, in RunHook
    parallel=parallel)
  File "C:\src\depot_tools\presubmit_support.py", line 1547, in DoPresubmitChecks
    results += executer.ExecPresubmitScript(presubmit_script, filename)
  File "C:\src\depot_tools\presubmit_support.py", line 1454, in ExecPresubmitScript
    result = eval(function_name + '(*__args)', context)
  File "<string>", line 1, in <module>
  File "<string>", line 447, in CheckChangeOnUpload
  File "<string>", line 310, in _CommonChecks
  File "C:\src\depot_tools\presubmit_canned_checks.py", line 887, in CheckOwners
    override_files=input_api.change.OriginalOwnersFiles())
  File "C:\src\depot_tools\owners_finder.py", line 40, in __init__
    self.db.load_data_needed_for(files)
  File "C:\src\depot_tools\owners.py", line 219, in load_data_needed_for
    self._read_owners(self.os_path.join(dirpath, 'OWNERS'))
  File "C:\src\depot_tools\owners.py", line 304, in _read_owners
    lineno, '\n'.join(comment + line_comment))
  File "C:\src\depot_tools\owners.py", line 363, in _add_entry
    include_file = self._resolve_include(directive[5:], owners_path, lineno)
  File "C:\src\depot_tools\owners.py", line 399, in _resolve_include
    raise SyntaxErrorInOwnersFile(start, lineno, 'file: include must specify '
SyntaxErrorInOwnersFile: C:\src\v8\include\OWNERS:8 syntax error: file: include must specify a file named OWNERS or ending in _OWNERS