[1/2] benchmarks.benchmark_smoke_unittest.BenchmarkSmokeTest.tab_switching.typical_25 failed unexpectedly 0.0000s:
  Failed to load "benchmarks.benchmark_smoke_unittest.BenchmarkSmokeTest.tab_switching.typical_25" in run_one_test
    loadTestsFromName("benchmarks.benchmark_smoke_unittest.BenchmarkSmokeTest.tab_switching.typical_25") failed: 'module' object has no attribute 'BenchmarkSmokeTest'
    Traceback (most recent call last):
      File "/b/s/w/ir/third_party/catapult/third_party/typ/typ/runner.py", line 822, in _run_one_test
      File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/unittest/loader.py", line 100, in loadTestsFromName
        parent, obj = obj, getattr(obj, part)
    AttributeError: 'module' object has no attribute 'BenchmarkSmokeTest'
    
    
    load_via_load_tests("benchmarks.benchmark_smoke_unittest.BenchmarkSmokeTest.tab_switching.typical_25") returned 0 tests
[2/2] measurements.clock_domain_test.ClockDomainTest.testTelemetryUsesChromeClockDomain failed unexpectedly 0.0014s:
  Chrome build location for mac_x86_64 not found. Browser will be run without Flash.
  Traceback (most recent call last):
    File "/b/s/w/ir/third_party/catapult/telemetry/telemetry/testing/browser_test_case.py", line 87, in setUpClass
  Exception: No browser found, cannot continue test.

First failing builds:
https://uberchromegw.corp.google.com/i/chromium.mac/builders/Mac10.11%20Tests/builds/15956
https://uberchromegw.corp.google.com/i/chromium.mac/builders/Mac10.10%20Tests/builds/21586

[28/29] benchmarks.benchmark_smoke_unittest.BenchmarkSmokeTest.tab_switching.typical_25 failed unexpectedly 431.2387s:
  [ RUN      ] multitab:misc:typical24@{'case': 'multitab', 'group': 'misc'}
  Traceback (most recent call last):
    File "/b/s/w/ir/third_party/catapult/telemetry/telemetry/internal/story_runner.py", line 105, in _RunStoryAndProcessErrorIfNeeded
    File "/b/s/w/ir/third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py", line 52, in traced_function
    File "/b/s/w/ir/third_party/catapult/telemetry/telemetry/page/shared_page_state.py", line 314, in RunStory
    File "/b/s/w/ir/third_party/catapult/telemetry/telemetry/page/__init__.py", line 108, in Run
    File "/b/s/w/ir/third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py", line 52, in traced_function
    File "/b/s/w/ir/third_party/catapult/telemetry/telemetry/page/legacy_page_test.py", line 177, in RunNavigateSteps
    File "/b/s/w/ir/tools/perf/page_sets/system_health/multi_tab_stories.py", line 29, in RunNavigateSteps
    File "/b/s/w/ir/third_party/catapult/telemetry/telemetry/internal/browser/tab_list.py", line 9, in New
    File "/b/s/w/ir/third_party/catapult/telemetry/telemetry/internal/backends/chrome/tab_list_backend.py", line 43, in New
    File "/b/s/w/ir/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_backend_list.py", line 75, in GetBackendFromContextId
    File "/b/s/w/ir/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/devtools_client_backend.py", line 478, in GetInspectorBackend
  KeyError: u'Cannot find a context with id=713500f3-2355-4465-936e-295dcb4b6871'
  

Appears to be fixed? +erikchen for telemetry + Mac FYI

Yeah, seems fixed.