Use Bazel-registry metadata.json repository field for sourceUrl (not just homepage)

[AlexanderLanin]

Summary

The bazel datasource should use the Bazel-registry metadata.json repository field to determine a module's sourceUrl, instead of relying solely on homepage.

Current behavior

For a bazel_dep (Bazel Central Registry or a compatible custom registry), the datasource parses only homepage, versions and yanked_versions from metadata.json:

// lib/modules/datasource/bazel/schema.ts
export const BazelModuleMetadata = z.object({
  homepage: z.string().optional().nullable(),
  versions: z.array(z.string()),
  yanked_versions: z.record(z.string(), z.string()).optional(),
});

lib/modules/datasource/bazel/index.ts then sets only result.homepage. Because no sourceUrl is provided, addMetaData() derives sourceUrl from homepage (lib/modules/datasource/metadata.ts).

The BCR metadata.json schema also defines a repository field (an array such as ["github:owner/repo"]) that is the canonical, machine-readable source location. Renovate ignores it today.

Why this is a problem

homepage is a human landing page and is frequently a docs site rather than the source repo. When it points at GitHub Pages (https://owner.github.io/project), the derived sourceUrl has a non-github.com host, and the GitHub changelog source rejects it:

DEBUG: Fetching changelog: https://<org>.github.io/<project> (x -> y)
DEBUG: Repository URL does not match any known github hosts - skipping changelog retrieval
       { "manager": "bazel-module", "packageName": "...", "sourceUrl": "https://<org>.github.io/<project>" }

Result: no release notes/changelogs are rendered, even though the module's metadata.json repository field correctly identifies the GitHub repo and that repo publishes GitHub Releases.

Concrete example

In the Eclipse SCORE Bazel registry, score_process and score_platform set:

• homepage: https://eclipse-score.github.io/process_description (GitHub Pages)
• repository: ["github:eclipse-score/process_description"]

Every update PR for these two modules is created with an empty release-notes section, while sibling modules whose homepage is a github.com URL (e.g. score_docs_as_code) render changelogs correctly. The repository field points at the right repo, but Renovate never reads it.

Current workaround (and why it's not enough)

The only workaround today is to change the registry data so homepage is the GitHub repo URL, e.g. this registry PR:
eclipse-score/bazel_registry#462 (sets homepage to https://github.com/eclipse-score/<repo>).

That works, but it forces registry maintainers to duplicate the repository value into homepage (and to sacrifice a legitimate docs-site homepage) purely to satisfy Renovate. Honoring repository would remove the need for this workaround entirely.

Proposed enhancement

In the bazel datasource:

1. Add repository to the parsed schema (array of "<host>:owner/repo" strings, per BCR).
2. When present, translate the first github:owner/repo entry into https://github.com/owner/repo and set it as sourceUrl on the ReleaseResult (also support gitlab: etc. where feasible).
3. Keep homepage as a fallback when repository is absent, preserving current behavior.

This makes changelog retrieval work for any BCR-style module whose homepage is a docs/Pages site, using the standards-defined field for exactly this purpose. It is backwards compatible (fallback to homepage is unchanged).

References

• BCR module metadata schema: metadata.json repository field.
• Concrete example + current workaround: fix: point score_process and score_platform homepage to GitHub repo (fixes Renovate release notes) eclipse-score/bazel_registry#462.
• Related discussion on Bazel-registry metadata gaps: bazel central registry lacks releaseTimestamp #42258 (releaseTimestamp).

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This idea was investigated and drafted with AI assistance (Claude Code), and reviewed by me before posting.

[RahulGautamSingh]

PR welcome