[tw-mbp-peiyu pants (master)]$ ./pants --enable-v2-engine -q changed --changes-since=HEAD^^
Exception caught: (<type 'exceptions.ValueError'>)
  File "/Users/peiyu/workspace/pants/src/python/pants/bin/pants_exe.py", line 50, in <module>
    main()
  File "/Users/peiyu/workspace/pants/src/python/pants/bin/pants_exe.py", line 44, in main
    PantsRunner(exiter).run()
  File "/Users/peiyu/workspace/pants/src/python/pants/bin/pants_runner.py", line 57, in run
    options_bootstrapper=options_bootstrapper)
  File "/Users/peiyu/workspace/pants/src/python/pants/bin/pants_runner.py", line 46, in _run
    return LocalPantsRunner(exiter, args, env, options_bootstrapper=options_bootstrapper).run()
  File "/Users/peiyu/workspace/pants/src/python/pants/bin/local_pants_runner.py", line 37, in run
    self._run()
  File "/Users/peiyu/workspace/pants/src/python/pants/bin/local_pants_runner.py", line 77, in _run
    self._exiter).setup()
  File "/Users/peiyu/workspace/pants/src/python/pants/bin/goal_runner.py", line 184, in setup
    goals, context = self._setup_context()
  File "/Users/peiyu/workspace/pants/src/python/pants/bin/goal_runner.py", line 157, in _setup_context
    self._daemon_graph_helper
  File "/Users/peiyu/workspace/pants/src/python/pants/bin/goal_runner.py", line 100, in _init_graph
    change_calculator=graph_helper.change_calculator)
  File "/Users/peiyu/workspace/pants/src/python/pants/bin/target_roots.py", line 72, in create
    changed_addresses = change_calculator.changed_target_addresses(changed_request)
  File "/Users/peiyu/workspace/pants/src/python/pants/engine/legacy/change_calculator.py", line 128, in changed_target_addresses
    return list(self.iter_changed_target_addresses(changed_request))
  File "/Users/peiyu/workspace/pants/src/python/pants/engine/legacy/change_calculator.py", line 107, in iter_changed_target_addresses
    in self._mapper.iter_target_addresses_for_sources(changed_files))
  File "/Users/peiyu/workspace/pants/src/python/pants/engine/legacy/change_calculator.py", line 105, in <genexpr>
    changed_addresses = set(address
  File "/Users/peiyu/workspace/pants/src/python/pants/engine/legacy/source_mapper.py", line 105, in iter_target_addresses_for_sources
    if any(source_file in sources_set for source_file in target_files_iter):
  File "/Users/peiyu/workspace/pants/src/python/pants/engine/legacy/source_mapper.py", line 105, in <genexpr>
    if any(source_file in sources_set for source_file in target_files_iter):
  File "/Users/peiyu/workspace/pants/src/python/pants/engine/legacy/source_mapper.py", line 87, in _iter_owned_files_from_hydrated_target
    raise ValueError('TODO: Not supported: see #4010.')

Exception message: TODO: Not supported: see #4010.