The e2e tests in CI taking 6 minutes seems really long

[metachris]

The e2e tests in CI taking 6 minutes seems really long... What are they doing that they can't figure out faster?

@niccoloraspa suggested caching Go modules, which might help, but probably not a lot. 5 minutes of the 6 overall are spent running the test: https://github.com/flashbots/builder-playground/actions/runs/21286952586/job/61270366780

[metachris]

@claude what's the change to add Go module caching?

[claude]

Claude finished @metachris's task in 37s —— View job

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Go Module Caching for CI

• Review current CI workflow configuration
• Identify where to add Go module caching
• Provide the recommended change

The current workflow is using actions/setup-go@v2 in most jobs, which is outdated. Modern versions of actions/setup-go (v4+) have built-in Go module caching that's enabled by default.

Recommended Changes

Update the setup-go action to v5 or v6 (the lint job already uses v6) and ensure caching is enabled:

- name: Set up Go
  uses: actions/setup-go@v5
  with:
    go-version: 1.25
    cache: true  # This is actually the default in v4+, but explicit is clearer

The key changes needed in .github/workflows/checks.yaml:

1. e2e-test job (line 29): Change actions/setup-go@v2 → actions/setup-go@v5
2. unit-test job (line 62): Change actions/setup-go@v2 → actions/setup-go@v5
3. integration-test job (line 80): Change actions/setup-go@v2 → actions/setup-go@v5
4. docs-check job (line 134): Change actions/setup-go@v2 → actions/setup-go@v5

The lint job is already using actions/setup-go@v6 which has caching enabled by default.

How It Works

actions/setup-go v4+ automatically caches:

• ~/go/pkg/mod (module cache)
• ~/.cache/go-build (build cache)

It uses the go.sum file as the cache key, so the cache is invalidated when dependencies change.

Expected Impact

Module caching will reduce the time spent on go mod download and rebuilding dependencies. However, as noted in the issue, the main time is spent in the actual test execution (5 minutes of the 6 total), so the improvement from caching will likely be modest - probably saving 15-45 seconds per job on the dependency download/build phase.

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Would you like me to implement this change?

[canercidam]

Fixed in #374.