https://logs.chromium.org/logs/chromeos/buildbucket/cr-buildbucket.appspot.com/8924269037793761536/+/steps/RegenPortageCache/0/stdout

03:47:43: INFO: RunCommand: cros_sdk -- egencache --update --repo chromiumos --jobs 32 in /b/swarming/w/ir/cache/cbuild/repository/src/third_party/chromiumos-overlay
!!! aux_get(): ebuild for 'sys-devel/arc-build-0.0.2-r1' does not exist at:
!!!            /mnt/host/source/src/third_party/chromiumos-overlay/sys-devel/arc-build/arc-build-0.0.2-r1.ebuild
Traceback (most recent call last):
  File "/usr/lib/python-exec/python2.7/egencache", line 1120, in <module>
    sys.exit(egencache_main(sys.argv[1:]))
  File "/usr/lib/python-exec/python2.7/egencache", line 1036, in egencache_main
    gen_cache.run()
  File "/usr/lib/python-exec/python2.7/egencache", line 368, in run
    signum = run_main_scheduler(self._regen)
  File "/usr/lib64/python2.7/site-packages/portage/util/_async/run_main_scheduler.py", line 27, in run_main_scheduler
    scheduler.wait()
  File "/usr/lib64/python2.7/site-packages/_emerge/AsynchronousTask.py", line 83, in wait
    self.scheduler.run_until_complete(self.async_wait())
  File "/usr/lib64/python2.7/site-packages/portage/util/_eventloop/EventLoop.py", line 831, in run_until_complete
    self.iteration()
  File "/usr/lib64/python2.7/site-packages/portage/util/_eventloop/EventLoop.py", line 285, in iteration
    return self._iteration(*args)
  File "/usr/lib64/python2.7/site-packages/portage/util/_eventloop/EventLoop.py", line 350, in _iteration
    if self._run_timeouts():
  File "/usr/lib64/python2.7/site-packages/portage/util/_eventloop/EventLoop.py", line 601, in _run_timeouts
    if self._run_idle_callbacks():
  File "/usr/lib64/python2.7/site-packages/portage/util/_eventloop/EventLoop.py", line 560, in _run_idle_callbacks
    if x._callback(*x._args):
  File "/usr/lib64/python2.7/site-packages/portage/util/_eventloop/EventLoop.py", line 101, in __call__
    self._callback(*self._args)
  File "/usr/lib64/python2.7/site-packages/_emerge/AsynchronousTask.py", line 84, in wait
    self._wait_hook()
  File "/usr/lib64/python2.7/site-packages/_emerge/AsynchronousTask.py", line 195, in _wait_hook
    self._exit_listener_stack.pop()(self)
  File "/usr/lib64/python2.7/site-packages/_emerge/MetadataRegen.py", line 150, in _task_exit
    AsyncScheduler._task_exit(self, metadata_process)
  File "/usr/lib64/python2.7/site-packages/portage/util/_async/AsyncScheduler.py", line 80, in _task_exit
    self._schedule()
  File "/usr/lib64/python2.7/site-packages/_emerge/PollScheduler.py", line 154, in _schedule
    self._schedule_tasks()
  File "/usr/lib64/python2.7/site-packages/portage/util/_async/AsyncScheduler.py", line 59, in _schedule_tasks
    task = self._next_task()
  File "/usr/lib64/python2.7/site-packages/_emerge/MetadataRegen.py", line 33, in _next_task
    return next(self._process_iter)
  File "/usr/lib64/python2.7/site-packages/_emerge/MetadataRegen.py", line 68, in _iter_metadata_processes
    cpv, ebuild_path, repo_path)
  File "/usr/lib64/python2.7/site-packages/portage/dbapi/porttree.py", line 566, in _pull_valid_cache
    raise PortageKeyError(cpv)
portage.exception.PortageKeyError: u'sys-devel/arc-build-0.0.2-r1'