Add macOS smoke coverage for released gc artifacts

[julianknutsen]

Problem

Gas City already publishes macOS release artifacts and has a Homebrew path, but launch validation still leans heavily on source builds and Linux-first contributor workflows.

That leaves packaging and macOS install regressions easy to miss until users hit them.

Scope

• verify a released macOS artifact or Homebrew install works on a clean machine
• run a minimal non-destructive sanity flow such as gc version, gc init, and one or two simple commands
• document the smoke path so maintainers can run it before releases

Acceptance Criteria

• there is an explicit macOS smoke procedure or automated check for released artifacts
• the smoke path exercises the installed binary, not only a source build
• failures are actionable and clearly tied to release validation

wasteland:
  type: bug
  priority: 1
  effort: small

[julianknutsen]

Wasteland sync — tracked as w-ac31f2e263

Field	Value
Wanted ID	w-ac31f2e263
Status	open
Upstream	hop/wl-commons

Last updated by Wendy patrol — 2026-04-06T06:19Z

[Rome-1]

Tracing against current main — this appears already done:

The smoke script exists: scripts/smoke-macos.sh (257 lines, committed in 8b2cf592 and extended in 0562f4ae). It:

• Downloads the released darwin artifact from GitHub releases (gascity_<version>_darwin_<arch>.tar.gz) — exercises the installed binary, not a source build.
• Runs gc version, gc version --long, gc help, gc doctor, and gc init against the downloaded binary.
• Defaults to a sandbox-exec jail (no network, restricted writes); GC_NO_SANDBOX=1 unlocks full gc init + in-city gc doctor.
• Emits explicit PASS/FAIL per test and exits non-zero on any failure.

The procedure is documented: CONTRIBUTING.md:102-116 has a "macOS Release Verification" section that tells maintainers to run it before tagging a release and after build/packaging changes.

Mapping to the acceptance criteria:

Criterion	Status
Explicit macOS smoke procedure or automated check for released artifacts	✅ scripts/smoke-macos.sh
Exercises installed binary, not only source build	✅ downloads from releases
Failures are actionable and clearly tied to release validation	✅ PASS/FAIL, non-zero exit, CONTRIBUTING.md ties it to the release flow

Gaps that could still be worth filing as a follow-up issue (but aren't what this one asked for):

1. No post-tag CI job that runs the smoke script against the just-published artifact (current release.yml stops at GoReleaser).
2. .github/workflows/mac-regression.yml runs make test on macOS but that's source builds, not released artifacts.

Suggesting this can be closed.