These all say "Could not open platform files for entry." and then crash like this:

Traceback (most recent call last):
  File "/b/swarm_slave/work/isolated/runZiyE30/third_party/catapult/telemetry/telemetry/internal/story_runner.py", line 84, in _RunStoryAndProcessErrorIfNeeded
    state.RunStory(results)
  File "/b/swarm_slave/work/isolated/runZiyE30/content/test/gpu/gpu_tests/gpu_test_base.py", line 111, in RunStory
    RunStoryWithRetries(GpuSharedPageState, self, results)
  File "/b/swarm_slave/work/isolated/runZiyE30/content/test/gpu/gpu_tests/gpu_test_base.py", line 72, in RunStoryWithRetries
    super(cls, shared_page_state).RunStory(results)
  File "/b/swarm_slave/work/isolated/runZiyE30/third_party/catapult/telemetry/telemetry/page/shared_page_state.py", line 326, in RunStory
    self._current_page, self._current_tab, results)
  File "/b/swarm_slave/work/isolated/runZiyE30/content/test/gpu/gpu_tests/maps.py", line 41, in ValidateAndMeasurePage
    screenshot = tab.Screenshot(5)
  File "/b/swarm_slave/work/isolated/runZiyE30/third_party/catapult/telemetry/telemetry/internal/browser/tab.py", line 117, in Screenshot
    return self._inspector_backend.Screenshot(timeout)
  File "/b/swarm_slave/work/isolated/runZiyE30/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_backend.py", line 35, in inner
    inspector_backend._ConvertExceptionFromInspectorWebsocket(e)
  File "/b/swarm_slave/work/isolated/runZiyE30/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_backend.py", line 32, in inner
    return func(inspector_backend, *args, **kwargs)
  File "/b/swarm_slave/work/isolated/runZiyE30/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_backend.py", line 139, in Screenshot
    return self._page.CaptureScreenshot(timeout)
  File "/b/swarm_slave/work/isolated/runZiyE30/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_page.py", line 146, in CaptureScreenshot
    res = self._inspector_websocket.SyncRequest(request, timeout)
  File "/b/swarm_slave/work/isolated/runZiyE30/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_websocket.py", line 110, in SyncRequest
    res = self._Receive(timeout)
  File "/b/swarm_slave/work/isolated/runZiyE30/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_websocket.py", line 149, in _Receive
    data = self._socket.recv()
  File "/b/swarm_slave/work/isolated/runZiyE30/third_party/catapult/telemetry/third_party/websocket-client/websocket.py", line 596, in recv
    opcode, data = self.recv_data()
  File "/b/swarm_slave/work/isolated/runZiyE30/third_party/catapult/telemetry/third_party/websocket-client/websocket.py", line 606, in recv_data
    frame = self.recv_frame()
  File "/b/swarm_slave/work/isolated/runZiyE30/third_party/catapult/telemetry/third_party/websocket-client/websocket.py", line 637, in recv_frame
    self._frame_header = self._recv_strict(2)
  File "/b/swarm_slave/work/isolated/runZiyE30/third_party/catapult/telemetry/third_party/websocket-client/websocket.py", line 746, in _recv_strict
    bytes = self._recv(shortage)
  File "/b/swarm_slave/work/isolated/runZiyE30/third_party/catapult/telemetry/third_party/websocket-client/websocket.py", line 732, in _recv
    raise WebSocketTimeoutException(e.message)
TimeoutException: 


I'm not overly familiar with how these tests run but I don't see how it could time-out waiting for local files so perhaps they're mounted from the network and access is sporadic.

It doesn't appear to be an issue with the test itself.

Detected 9 new flakes for test/step "maps_pixel_test (with patch)". To see the actual flakes, please visit https://chromium-try-flakes.appspot.com/all_flake_occurrences?key=ahVzfmNocm9taXVtLXRyeS1mbGFrZXNyJwsSBUZsYWtlIhxtYXBzX3BpeGVsX3Rlc3QgKHdpdGggcGF0Y2gpDA. This message was posted automatically by the chromium-try-flakes app. Since flakiness is ongoing, the issue was moved back into Sheriff Bug Queue (unless already there).

I'm not sure what to do with the flakiness here. Maybe Labs have thoughts about the network?

This looks like https://bugs.chromium.org/p/chromium/issues/detail?id=605243 as the shards referenced in the failed tests were run on build208-m4 and build210-m4.

Haven't seen any new reports in the last 24 hours, so I'm closing this.

 Issue 609630  has been merged into this issue.

Re-opening, as the flakes have occurred again (see merged issue).

(+dba, context: possible reoccurrence of https://bugs.chromium.org/p/chromium/issues/detail?id=605243)

It seems it is not related to machine state this time. All failures I checked happen on different machines (build211-m4, build223-m4, build220-m4, build470-m4, build215-m4), and the tests succeeds on these same machines later (e.g. https://chromium-swarm.appspot.com/user/task/2e9f9230a80b1011)

"Could not open platform files for entry." is red herring. Successful runs also have this line: https://chromium-swarm.appspot.com/user/task/2e9fc3c9b955a010

Too me it looks like a genuine flake in the test, not the bot.

Detected 3 new flakes for test/step "maps_pixel_test (with patch)". To see the actual flakes, please visit https://chromium-try-flakes.appspot.com/all_flake_occurrences?key=ahVzfmNocm9taXVtLXRyeS1mbGFrZXNyJwsSBUZsYWtlIhxtYXBzX3BpeGVsX3Rlc3QgKHdpdGggcGF0Y2gpDA. This message was posted automatically by the chromium-try-flakes app. Since flakiness is ongoing, the issue was moved back into Sheriff Bug Queue (unless already there).

Infra-Troopers@, could you find an owner for this issue?

It looks this issue is still happening. Due to that, this entry has been in a sheriff-o-mattic.

Detected 3 new flakes for test/step "maps_pixel_test (with patch)". To see the actual flakes, please visit https://chromium-try-flakes.appspot.com/all_flake_occurrences?key=ahVzfmNocm9taXVtLXRyeS1mbGFrZXNyJwsSBUZsYWtlIhxtYXBzX3BpeGVsX3Rlc3QgKHdpdGggcGF0Y2gpDA. This message was posted automatically by the chromium-try-flakes app. Since flakiness is ongoing, the issue was moved back into Sheriff Bug Queue (unless already there).

The crash that I can see is in the telemetry inspector backend:

...
  File "/b/swarm_slave/work/isolated/runjJF7Hq/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_websocket.py", line 179, in _HandleNotification
    self._domain_handlers[domain_name](result)
  File "/b/swarm_slave/work/isolated/runjJF7Hq/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_backend.py", line 288, in _HandleInspectorDomainNotification
    raise exception

This doesn't look like a problem with infrastructure...

This doesn't appear to be either infra or telemetry, as far as I can see (from the most recent failure, anyway.) Telemetry is reporting (through the devtools protocol) that the tab has crashed.

There's an extensive 20 thread stack trace right after that line that shows a segfault within V8, as the v8::scope is being destructed.

From https://uberchromegw.corp.google.com/i/chromium.gpu/builders/Mac%2010.10%20Debug%20%28Intel%29/builds/8048/steps/maps_pixel_test%20on%20Intel%20GPU%20on%20Mac%20on%20Mac-10.10/logs/stdio :

	Crash reason:  EXC_BAD_ACCESS / KERN_INVALID_ADDRESS
	Crash address: 0x9ffffffff
	Process uptime: 3 seconds
	
	Thread 0 (crashed)
	 0  libv8.dylib!v8::Context::Exit() + 0x112
	    rax = 0x0000000a00000000   rdx = 0x0000000000000002
	    rcx = 0x00007fe4fb43cec0   rbx = 0x00007fe4fc829820
	    rsi = 0x00007fe4fb507330   rdi = 0x00007fe4fc861178
	    rbp = 0x00007fff588669d0   rsp = 0x00007fff588669b0
	     r8 = 0x00000000000000b2    r9 = 0x00000000ffff0000
	    r10 = 0x00007fe4fb400000   r11 = 0x0000000000000005
	    r12 = 0x000000000000003b   r13 = 0x0000000000000000
	    r14 = 0x0000000000000004   r15 = 0x00007fe4fb814c00
	    rip = 0x0000000123e298f2
	    Found by: given as instruction pointer in context
	 1  libwebcore_shared.dylib!blink::V8CSSStyleDeclaration::visitDOMWrapper(v8::Isolate*, blink::ScriptWrappable*, v8::Persistent<v8::Object, v8::NonCopyablePersistentTraits<v8::Object> > const&) + 0x215
	    rbx = 0x00007fe4fb815360   rbp = 0x00007fff58866ae0
	    rsp = 0x00007fff588669e0   r12 = 0x000000000000003b
	    r13 = 0x0000000000000000   r14 = 0x00007fff58866db0
	    r15 = 0x00007fe4fb814c00   rip = 0x000000012805a2c5
	    Found by: call frame info
[ Followed by 104 more stack frames, then 19 more threads ]

Eric -- I've seen your username around GPU testing commits in this area -- could you take a look, or help find someone who can take this one?

Detected 7 new flakes for test/step "maps_pixel_test (with patch)". To see the actual flakes, please visit https://chromium-try-flakes.appspot.com/all_flake_occurrences?key=ahVzfmNocm9taXVtLXRyeS1mbGFrZXNyJwsSBUZsYWtlIhxtYXBzX3BpeGVsX3Rlc3QgKHdpdGggcGF0Y2gpDA. This message was posted automatically by the chromium-try-flakes app. Since flakiness is ongoing, the issue was moved back into Sheriff Bug Queue (unless already there).

Issue assigned; removing Sheriff label.

I triaged these crashes yesterday and filed  Issue 610340  about them. Sorry I didn't see this bug in the meantime, but duplicating it into the other one.