Overlays: allow any build mode for Go

[nickrolfe]

We have a check that a traced language can only run overlay analysis with build-mode: none, but Go does not currently declare support for BMN, even though it has a similar autobuild mode that will work for overlay analysis.

This commit adds a hard-coded exception to that check, allowing any build mode for Go. This is intended as a short-term solution until Go declares BMN support.

For now, it should be safe to enable for all build modes:

• We can still control rollout, via the overlay feature flags, to repos we know will work correctly.
• It allows us to see what happens for manual builds.
• We should be able to ensure that the Go extractor/autobuilder fail for unsupported build configures in such a way that we fall back to full analysis.

Risk assessment

For internal use only. Please select the risk level of this change:

• Low risk: Changes are fully under feature flags, or have been fully tested and validated in pre-production environments and are highly observable, or are documentation or test only.

Which use cases does this change impact?

• Advanced setup - Impacts users who have custom workflows.
• Default setup - Impacts users who use default setup.
• Code Scanning - Impacts Code Scanning (i.e. analysis-kinds: code-scanning).
• Code Quality - Impacts Code Quality (i.e. analysis-kinds: code-quality).

How did/will you validate this change?

• None - I am not validating these changes specifically, but I have been testing overlay analysis for Go in general.

If something goes wrong after this change is released, what are the mitigation and rollback strategies?

• Feature flags - All new or changed code paths can be fully disabled with corresponding feature flags.

How will you know if something goes wrong after this change is released?

• Telemetry - I rely on existing telemetry or have made changes to the telemetry.
  • Dashboards - I will watch relevant dashboards for issues after the release. Consider whether this requires this change to be released at a particular time rather than as part of a regular release.
  • Alerts - New or existing monitors will trip if something goes wrong with this change.

Merge / deployment checklist

• Confirm this change is backwards compatible with existing workflows.
• Consider adding a changelog entry for this change.
• Confirm the readme and docs have been updated if necessary.

[Copilot]

Pull Request Overview

This PR adds a workaround to allow Go overlay analysis to work with any build mode, bypassing the normal restriction that requires build-mode: none for traced languages. The change introduces a hard-coded exception for Go since it doesn't currently declare Build Mode None (BMN) support but has equivalent autobuild capabilities.

Key changes:

• Added Go-specific exception in overlay database mode validation
• Modified the traced language check to exclude Go from the build mode restriction

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/config-utils.ts	Added Go exception in getOverlayDatabaseMode function to bypass build mode validation
lib/init-action.js	Generated JavaScript equivalent of the TypeScript changes

[Copilot]

The hard-coded Go exception creates a maintenance burden and breaks the logical flow. Consider extracting this logic into a helper function like shouldCheckBuildModeForLanguage(language) to improve readability and make future language exceptions easier to manage.

[henrymercer]

You mention:

even though it has a similar autobuild mode that will work for overlay analysis

but this PR enables overlay for workflows using manual build steps too. Will those setups work too with overlay?

[nickrolfe]

I've updated the PR description and code comment to mention that the Go extractor/autobuilder will aim to ensure that we fall back to full analysis for build setups that won't work with overlays.

[henrymercer]

Thanks for the extra context!