Just tried uploading a CL, and `git cl upload` died like so:

** Presubmit Warnings **
tests/git_common_test.py (13.77s) failed
..F....................F.......uCannot foo with a dirty tree. You must commit locally first.
Uncommitted files: (git diff-index --name-status HEAD)
A	test.file
.......
======================================================================
FAIL: testMakeWorkdir (__main__.GitMakeWorkdir)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests/git_common_test.py", line 833, in testMakeWorkdir
    os.path.join(self.repo.repo_path, '.git', path))
AssertionError: '/private/var/folders/c5/8d7sdn1x2mg92mj0rndghhdr0000gn/T/git_repoRdkQFkbase/tmprVOD5v/.git/config' != '/var/folders/c5/8d7sdn1x2mg92mj0rndghhdr0000gn/T/git_repoRdkQFkbase/tmprVOD5v/.git/config'

======================================================================
FAIL: testRepoRoot (__main__.GitReadOnlyFunctionsTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "tests/git_common_test.py", line 340, in testRepoRoot
    self.assertEqual(self.repo.repo_path, self.repo.run(self.gc.repo_root))
AssertionError: '/var/folders/c5/8d7sdn1x2mg92mj0rndghhdr0000gn/T/git_repoRdkQFkbase/tmpTfAVZl' != '/private/var/folders/c5/8d7sdn1x2mg92mj0rndghhdr0000gn/T/git_repoRdkQFkbase/tmpTfAVZl'

----------------------------------------------------------------------
Ran 39 tests in 13.277s

FAILED (failures=2, unexpected successes=1)
Name         Stmts   Miss  Cover   Missing
------------------------------------------
git_common     437      0   100%   


tests/git_number_test.py (0.14s) failed
ERROR: python-coverage (3.7) is required to be installed on your PYTHONPATH to run this test.


tests/presubmit_unittest.py (4.76s) failed
..................................................................................................E...............E
======================================================================
ERROR: testExecPresubmitScript (__main__.PresubmitUnittest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/thakis/src/depot_tools/third_party/pymox/mox.py", line 1618, in new_method
    func(self, *args, **kwargs)
  File "tests/presubmit_unittest.py", line 663, in testExecPresubmitScript
    fake_presubmit)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/unittest/case.py", line 475, in assertRaises
    callableObj(*args, **kwargs)
  File "/Users/thakis/src/depot_tools/presubmit_support.py", line 1380, in ExecPresubmitScript
    self.rietveld, self.verbose)
  File "/Users/thakis/src/depot_tools/presubmit_support.py", line 323, in __init__
    self._run_tests_pool = multiprocessing.Pool(self.cpu_count)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/multiprocessing/__init__.py", line 232, in Pool
    return Pool(processes, initializer, initargs, maxtasksperchild)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/multiprocessing/pool.py", line 138, in __init__
    self._setup_queues()
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/multiprocessing/pool.py", line 235, in _setup_queues
    self._outqueue = SimpleQueue()
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/multiprocessing/queues.py", line 353, in __init__
    self._reader, self._writer = Pipe(duplex=False)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/multiprocessing/__init__.py", line 107, in Pipe
    return Pipe(duplex)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/multiprocessing/connection.py", line 196, in Pipe
    fd1, fd2 = os.pipe()
OSError: [Errno 24] Too many open files

======================================================================
ERROR: testTags (__main__.PresubmitUnittest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/thakis/src/depot_tools/third_party/pymox/mox.py", line 1618, in new_method
    func(self, *args, **kwargs)
  File "tests/presubmit_unittest.py", line 913, in testTags
    change, False, True, output, input_buf, DEFAULT_SCRIPT, False, None))
  File "/Users/thakis/src/depot_tools/presubmit_support.py", line 1472, in DoPresubmitChecks
    results += executer.ExecPresubmitScript(default_presubmit, fake_path)
  File "/Users/thakis/src/depot_tools/presubmit_support.py", line 1380, in ExecPresubmitScript
    self.rietveld, self.verbose)
  File "/Users/thakis/src/depot_tools/presubmit_support.py", line 323, in __init__
    self._run_tests_pool = multiprocessing.Pool(self.cpu_count)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/multiprocessing/__init__.py", line 232, in Pool
    return Pool(processes, initializer, initargs, maxtasksperchild)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/multiprocessing/pool.py", line 138, in __init__
    self._setup_queues()
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/multiprocessing/pool.py", line 235, in _setup_queues
    self._outqueue = SimpleQueue()
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/multiprocessing/queues.py", line 353, in __init__
    self._reader, self._writer = Pipe(duplex=False)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/multiprocessing/__init__.py", line 107, in Pipe
    return Pipe(duplex)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/multiprocessing/connection.py", line 196, in Pipe
    fd1, fd2 = os.pipe()
OSError: [Errno 24] Too many open files

----------------------------------------------------------------------
Ran 115 tests in 1.902s

FAILED (errors=2)


tests/recipes_test.py (2.39s) failed
fatal: Needed a single revision
From https://chromium.googlesource.com/a/external/github.com/luci/recipes-py
   7d340be..d903931  master     -> origin/master
Traceback (most recent call last):
  File "/Users/thakis/src/depot_tools/.recipe_deps/recipe_engine/recipes.py", line 442, in <module>
    sys.exit(main())
  File "/Users/thakis/src/depot_tools/.recipe_deps/recipe_engine/recipes.py", line 406, in main
    return simulation_test(package_deps, args)
  File "/Users/thakis/src/depot_tools/.recipe_deps/recipe_engine/recipes.py", line 36, in simulation_test
    from recipe_engine import simulation_test
  File "/Users/thakis/src/depot_tools/.recipe_deps/recipe_engine/recipe_engine/simulation_test.py", line 12, in <module>
    from .third_party import expect_tests
  File "/Users/thakis/src/depot_tools/.recipe_deps/recipe_engine/recipe_engine/third_party/expect_tests/__init__.py", line 5, in <module>
    from .main import main
  File "/Users/thakis/src/depot_tools/.recipe_deps/recipe_engine/recipe_engine/third_party/expect_tests/main.py", line 9, in <module>
    from .cover import CoverageContext
  File "/Users/thakis/src/depot_tools/.recipe_deps/recipe_engine/recipe_engine/third_party/expect_tests/cover.py", line 10, in <module>
    import coverage
ImportError: No module named coverage
Traceback (most recent call last):
  File "tests/recipes_test.py", line 17, in <module>
    recipes_py('simulation_test')
  File "tests/recipes_test.py", line 15, in recipes_py
    subprocess.check_call([os.path.join(ROOT_DIR, 'recipes.py')] + list(args))
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 540, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['/Users/thakis/src/depot_tools/recipes.py', 'simulation_test']' returned non-zero exit status 1


Presubmit checks took 32.5s to calculate.