[CI] Retry flaky-test artifact downloads

[CoffeeDrivenCoder]

Description

Fixes #4054. The flaky-test tracker currently fails the whole analysis job when a GitHub Actions artifact download encounters a transient connection reset, TLS error, or retryable 5xx/429 response.

Artifact downloads now retry request exceptions and transient HTTP statuses with bounded exponential backoff, while permanent HTTP errors still fail fast.

Motivation and Context

The failed tracker runs in #4054 show ConnectionResetError and SSLCertVerificationError while downloading artifact archives from GitHub. The API requests succeed, but the redirected artifact request is not retried.

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Checklist

• I have read the CONTRIBUTION guide.
• I have updated the tests accordingly.

Validation

• python -m pytest -q .github/scripts/test_analyze_flaky_tests.py
• python -m ruff check --ignore EXE001,PERF102 .github/scripts/analyze_flaky_tests.py .github/scripts/test_analyze_flaky_tests.py
• Existing TorchRL CPU/GPU regression tests for the tracked flaky-test entries pass locally.

Disclosure

AI assistance was used for repository exploration and drafting. I reviewed the implementation and ran the validation commands above.

[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/rl/4153

• 📄 Preview Python docs built from this PR

Note: Links to docs will display an error until the docs builds have been completed.

❌ 2 New Failures, 1 Unrelated Failure

As of commit 9900f33 with merge base 236e29a ():

NEW FAILURES - The following jobs have failed:

• SOTA Tests on Linux / tests (3.10, 13.0, 1) / linux-job (gh)
  RuntimeError: Command docker exec -t a7ed80bf61097e43cf9c4301afceb294932768c20cb88f3fa6d35e9a88a7b2ea /exec failed with exit code 1
• SOTA Tests on Linux / tests (3.10, 13.0, 2) / linux-job (gh)
  RuntimeError: Command docker exec -t a4103cecbcb9aae585c36106697aba849147fb2aea79e8eca3a57dce7a3ed291 /exec failed with exit code 1

BROKEN TRUNK - The following job failed but were present on the merge base:

👉 Rebase onto the `viable/strict` branch to avoid these failures

• Libs Tests on Linux / unittests-gym (3.10, 12.8) / linux-job (gh) (trunk failure)
  test/libs/test_gym.py::TestGym::test_gym[True-True-1-HalfCheetah-v4]

This comment was automatically generated by Dr. CI and updates every 15 minutes.

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[github-actions]

⚠️ PR Title Label Error

PR title must start with a label prefix in brackets (e.g., [BugFix]).

Current title: CI: retry flaky-test artifact downloads

Supported Prefixes (case-sensitive)

Your PR title must start with exactly one of these prefixes:

Prefix	Label Applied	Example
[Algorithm]	new algo	[Algorithm] Add new RL objective
[BE]	BE	[BE] Improve error messages
[Benchmark] or [Benchmarks]	Benchmarks	[Benchmark] Add collector benchmark
[BugFix]	BugFix	[BugFix] Fix memory leak in collector
[Example] or [Examples]	Examples	[Example] Add training script
[Feature]	Feature	[Feature] Add new optimizer
[Doc] or [Docs]	Documentation	[Doc] Update installation guide
[Refactor]	Refactoring	[Refactor] Clean up module imports
[CI]	CI	[CI] Fix workflow permissions
[Test] or [Tests]	Tests	[Tests] Add unit tests for buffer
[Trainer] or [Trainers]	Trainers	[Trainer] Add trainer config
[Environment] or [Environments]	Environments	[Environments] Add Gymnasium support
[Data]	Data	[Data] Fix replay buffer sampling
[LLM]	llm/	[LLM] Add reward model integration
[Minor]	small change	[Minor] Fix typo in error message
[Performance] or [Perf]	Performance	[Performance] Optimize tensor ops
[BC-Breaking]	bc breaking	[BC-Breaking] Remove deprecated API
[Deprecation]	Deprecation	[Deprecation] Mark old function
[Algorithm] or [Algorithms]	new algo	[Algorithm] Add new objective
[Quality]	Quality	[Quality] Fix typos and add codespell
[Versioning]	versioning	[Versioning] Bump release version
[WIP]	WIP	[WIP] Draft implementation

Note: Common variations like singular/plural are supported (e.g., [Doc] or [Docs]).

[meta-cla]

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[CoffeeDrivenCoder]

Thanks for the follow-up commit. The latest CI still shows one new Dreamer test failure and the known Gym trunk failure. I don’t have permission to rerun failed jobs (GitHub returns HTTP 403). Could a maintainer please rerun the failed jobs when convenient?

[gtnv]

Retry-After: 120 slept for 2 seconds in my probe. every retry can land inside the same cooldown. can a 429 honor Retry-After before local backoff?

[CoffeeDrivenCoder]

Thanks for catching this. Commit 9900f33 now honors the Retry-After header for 429 responses, using the larger of the server-provided delay and the local exponential backoff. It supports both delay-seconds and HTTP-date values and adds regression coverage. Focused local tests pass: 4 passed.