If I launch the -firmware-tryjob variant of the build for a board, it fails 

even though it's just a build of master without any modification
e.g.:
cros tryjob meowth-firmware-tryjob

I have got the following failed build for the command above:
https://uberchromegw.corp.google.com/i/chromiumos.tryserver/builders/firmware/builds/164
where the UploadTestArtifacts stage has failed with the following backtrace:
Traceback (most recent call last):
  File "/b/c/cbuild/repository/chromite/lib/parallel.py", line 442, in _Run
    self._task(*self._task_args, **self._task_kwargs)
  File "/b/c/cbuild/repository/chromite/cbuildbot/stages/artifact_stages.py", line 685, in BuildAutotestTarballs
    self._build_root, cwd, tempdir)
  File "/b/c/cbuild/repository/chromite/cbuildbot/commands.py", line 2057, in BuildAutotestControlFilesTarball
    exclude_dirs=['autotest/test_suites'])
  File "/b/c/cbuild/repository/chromite/cbuildbot/commands.py", line 2030, in FindFilesWithPattern
    os.chdir(cwd)
OSError: [Errno 2] No such file or directory: '/b/c/cbuild/repository/chroot/build/meowth/usr/local/build'

I guess /usr/local/build is supposed to contain the autotest files,
maybe we can just fail gracefully here (nothing to do)