Add EMTEST_RETRY_COUNT to force retrying failed tests #25565
Merged
+46
−5
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
…y and all failing tests as flaky.
sbc100
changed the title
sbc100
approved these changes
Oct 16, 2025
| retries_left = test_retry_count | ||
|
|
||
| num_fails = len(result.failures) | ||
| num_errors = len(result.errors) |
There was a problem hiding this comment.
Are these part of the non-parallel test runner too?
There was a problem hiding this comment.
Yes, these are part of the default unittest.py unittest.TestCase implementation. Had to add them to the parallel test runner to match the shape of the upstream Python implementation. Verified that this works in single-threaded and parallel test runner.
sbc100
approved these changes
Oct 16, 2025
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The way this differs from the existing EMTEST_RETRY_FLAKY is that this retries any failed test, whereas EMTEST_RETRY_FLAKY only retries those tests that had explicitly been deemed to be flaky beforehand.
The rationale for adding this feature is twofold:
There is currently so much flakiness in tests in the current test suites, that I would be flagging flaky tests for many months to come in my own CI. It is unclear if some of that flakiness is a harness problem or a systemic problem rather than an individual test problem, so I could end up flagging a majority of all tests in the suites as flaky.
Whenever a test fails in my CI, the very first thing I need to check is whether the failure was just a one-off, or whether the failure was a deterministic failure. So being able to run with
EMTEST_RETRY_COUNT=5will automate such testing for me and immediately give me feedback whether any test failure was deterministic or intermittent.