mono: migrate source to GitHub tag via gs:// mirror (6.12.0.199 → 6.12.0.206)

[bryan-minimal]

mono: migrate source to GitHub tag + gs:// mirror

Migrates mono off download.mono-project.com — a Microsoft-archived Azure blob (last modified 2024-05) that could vanish and leave the package unsourceable — to our archive bucket, sourced from the GitHub tag. (task #134)

What changed

• Source → gs://minimal-staging-archives/mono/mono/mono-%{version}.tar.gz, a prepared git archive --recurse-submodules of GitHub tag mono-6.12.0.206 (commit 0cbf0e2). The mono/mono repo has no release asset and the GitHub auto-archive omits the external/ submodules, so the prepared tarball bundles the full source + submodule trees (boringssl / bdwgc / llvm-project / cecil / …). sha256 pinned.
• Version 6.12.0.199 → 6.12.0.206. .199 only ever existed as a mono-project.com release blob, so it can't be sourced from GitHub at all; moved to the latest tag (a 7-commit patch range).
• build.sh:
  • .tar.xz → .tar.gz.
  • The prepared tarball ships the raw tag tree (no generated configure), so it now runs NOCONFIGURE=1 ./autogen.sh first to regenerate the autotools build system (+ m4 build dep, matching packages/check).
  • Strips the AppleDouble ._* sidecar files the macOS archiver scattered through the tree — mono's *.cs glob otherwise feeds these binary sidecars to the C# compiler (CS1056 "unexpected character" on e.g. external/cecil/Mono.Cecil.PE/._TextMap.cs).

Verification (built locally before opening)

Clean-room build (minimal package mono, arm64/linux) verified end-to-end through fetch → sha256 verify → extract → ._* strip → autogen.sh → configure → make, past the external/cecil class-lib compile that the ._* strip fixes. Handing the full build to buildbot from here (faster than a local machine for mono).

Reviewer notes

• The ._* strip is defensive and recurrence-safe (protects any future macOS-prepared mono tarball). The alternative is re-uploading a cleaned tarball with a new sha256 — happy to switch if you'd rather the hosted artifact be ._*-free at rest.
• source_provenance stays GithubRepo mono/mono (consistent with how age/acl/etc. declare a GithubRepo provenance while sourcing the bytes from the gs:// mirror).

🤖 Generated with Claude Code

Summary by CodeRabbit

• Chores
  • Updated Mono runtime to version 6.12.0.206.
  • Improved build process with updated package source and extraction method.
  • Enhanced build system configuration for compatibility with source distribution format.
  • Removed macOS-specific sidecar files during build to prevent potential conflicts.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: f3842ed1-eb48-488c-8679-59ecd75afd63

📥 Commits

Reviewing files that changed from the base of the PR and between 0a675d1 and 62fcd36.

📒 Files selected for processing (2)

• packages/mono/build.ncl
• packages/mono/build.sh

---

📝 Walkthrough

Walkthrough

Mono is updated from version 6.12.0.199 to 6.12.0.206 with a source location change from a Microsoft-hosted tar.xz to a Google Cloud Storage tar.gz archive. The build script is adapted to extract the new format, remove macOS metadata sidecar files, and regenerate autotools before building.

Changes

Mono Build Configuration and Script

Layer / File(s)	Summary
Build configuration and inputs packages/mono/build.ncl	Mono version bumped to 6.12.0.206, m4 dependency added, and download source switched from download.mono-project.com tar.xz to Google Cloud Storage tar.gz with updated SHA-256 checksum.
Build script extraction and preparation packages/mono/build.sh	Tarball extraction changes from .tar.xz to .tar.gz, macOS AppleDouble sidecar files (._*) are removed from the unpacked tree, and autotools build system is regenerated via autogen.sh before configure.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

A rabbit hops through build stacks with cheer,
Mono climbs versions, oh so dear!
From tar.xz to tar.gz we hop,
Sidecar files removed—no flop!
Autotools dance, configure awaits,
hops ✨ The build process celebrates!

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely summarizes the main change: migrating mono source to a GitHub tag via gs:// mirror with a version bump, which aligns with all changes in both build.ncl and build.sh files.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch mono-gs-source-206

---

_{Comment @coderabbitai help to get the list of available commands and usage tips.}