Handling Test Failures

ANGLE is tested by a number of test suites, including by the ANGLE CI and Try testers, and by the Chromium FYI testers. See pointers and explanations in the ANGLE Wrangling documentation.

We run a large number of tests for each ANGLE CL, both in ANGLE standalone and Chromium configurations, both pre- and post- commit. Some tests will fail, crash, or timeout. If these cannot be addressed in a timely manner, file a bug and update test expectations files. Timeliness depends on the context. For example, a Wrangler trying to unblock an AutoRoller will typically suppress failures immediately; where a developer will typically delay landing their CL in favor of fixing test failures.

Handling a Vulkan Validation Layer error

Many tests are run with an option that enables the Vulkan Validation Layers (sometimes referred to as VVL). Validation errors will cause an otherwise-passing test to fail.

The vulkan-deps into ANGLE AutoRoller updates ANGLE to the top-of-tree (ToT) upstream Vulkan tools and SDK. Sometimes validation errors are the result of bugs in the Vulkan Validation Layers, sometimes because of bugs in ANGLE. Therefore, investigate the cause of the error and determine if it‘s an ANGLE bug or a Vulkan Validation Layer bug. For Vulkan Validation Layer bugs, file an upstream bug, and suppress the error. The ANGLE Wrangler will also suppress a validation error when the vulkan-deps AutoRoller introduces a new validation error. The ANGLE Wrangler isn’t expected to resolve the error or diagnose an upstream bug (but it is welcome as extra credit).

Handle a validation error by doing the following:

  1. File an ANGLE bug. If this is an active Wrangler issue, set the Label Hotlist-Wrangler on the bug.
  2. Add the VVL error tag to the kSkippedMessages array in vk_renderer.cpp file. Follow the pattern for adding a comment with the associated bug in the line above the VVL tag.

dEQP test expectations

There are a set of dEQP expectations files in the src/tests/deqp_support directory. Notice the format of a line and your choices for OS, driver, etc. This is described in the directory's README.md file. This includes:

  • FLAKY - For rare flakes
  • FAIL - For a test that flakes often or persistently fails
  • SKIP - For a test that crashes
  • TIMEOUT - For a test that is very slow and may timeout

angle_end2end_tests expectations

These expectations all live in the angle_end2end_tests_expectations.txt file. The file format is the same as for the dEQP expectations. However, FAIL and FLAKY are not valid, and so the choices are:

  • SKIP - For a test that fails or crashes
  • TIMEOUT - For a test that is very slow and may timeout

Rubber stamping expectations CLs

CLs that only change dEQP or angle_end2end_tests expectations don't require a human reviewer and can be Rubber Stamped. The procedure is:

  1. Add rubber-stamper@appspot.gserviceaccount.com as the reviewer on the expectations CL. Please also CC a human reviewer for TBR.
  2. After 1 minute, Rubber Stamper should set “Bot-Commit: +1” on the CL.
  3. Now you should be able to “Commit-Queue: +2” your CL.

WebGL conformance test expectations

The expectations files are hosted in the chromium/src repository under content/test/gpu/gpu_tests/test_expectations. Note that this is not included in local ANGLE-only source tree.

The format of the file, including the different tags, is documented at the top of the file. This includes the following results:

  • RetryOnFailure - For a test that rarely flakes
  • Failure - For a test that fails consistently or flakes often
  • Skip - For a test that causes catastrophic failures (e.g. ends an entire test run, causes a bot to BSoD); Skip should be used very sparingly

You will need to contact an OWNER of the file to +1 your CL.

You have two options for creating a CL to the expectations files:

  1. For trivial edits, you can edit the expectations files via Chromium Code Search:
    • In the browser, press the Edit code button. This will bring up a new browser window/tab, in an editor mode.
    • Edit the expecations and then press the Create change (or Update change button if you need to change your CL later), which will create a CL.
  2. Otherwise please check out the code and upload a CL

“internal swarming failure” on one of the test shards

This might be caused by a bad bot, clicking on link “Bot assigned to task” will show recent tasks which might look bad (for example, lots of BOT_DIED in crbug.com/1350556). The best course of action in this case is to stop the bot by clicking the “stop the bot gracefully” button which will result in a task that looks like “Terminate build117-a9”, then open a bug in the Infra>Labs component. Googlers, see also: go/gpu-pixel-wrangler-how-to#manually-taking-a-machine-out-of-the-swarming-pool

Requesting access to the Commit Queue and issue tracker

If you need to request access for a user (or yourself) please ask a project owner to help. Googlers, email angle-team@google.com. External users, find a couple owners in the OWNERS file and send a request via email.

If you are an ANGLE owner and you want to grant a user access: