[mitchelljphayes]

Summary

Patch the v0.1.0 Homebrew Formula so brew install --build-from-source switcheroo and brew test switcheroo succeed under Homebrew's build sandbox.

This is a patch release (0.1.0 → 0.1.1). No daemon, config, service-definition, or remapping changes. No new functionality.

Sandbox bug (root cause)

iconutil -c icns cannot run inside Homebrew's build sandbox. Homebrew's seatbelt profile denies a mach-lookup that iconutil requires to load its IconServices framework — the call fails with "Invalid Iconset" even when the input iconset is perfectly valid and the same exact command succeeds a millisecond later outside the sandbox.

The v0.1.0 Formula generated the .icns at install time via sips + iconutil + Dir.mktmpdir. That worked on a developer machine, failed under brew install --build-from-source.

A second, smaller issue: Formula#system's Sorbet sig does not accept out: / err: keyword arguments, so the out: File::NULL, err: File::NULL calls raised TypeError: Expected type T.any(Integer, Pathname, String, Symbol), got type Hash under HOMEBREW_SORBET_RUNTIME=1 (set by brew test).

A third: the published v0.1.0 tap uses name macos: "homebrew.mxcl.switcheroo" for the launchd Label, so the Formula template must use the name macos: form too.

Fix (static asset copy)

Replace runtime .icns generation with a pre-built bundle/AppIcon.icns copied at install time:

• bundle/AppIcon.icns is now a tracked binary asset (generated outside the sandbox from bundle/AppIcon-1024.png using the 10 standard iconutil-recognized sizes: 16, 32, 128, 256, 512 + @2x each — not the 12-file set that includes the non-standard icon_64x64 pair iconutil silently ignores).
• Formula install block now: cp icns_source, app/"Contents/Resources/AppIcon.icns" — no sips, no iconutil, no Dir.mktmpdir, no out:/err: kwargs.
• scripts/generate_icns.sh regenerates the asset from the master PNG and validates output (ICNS magic, declared length, chunk-length sum, round-trip decode via iconutil -c iconset).
• scripts/package.sh now prefers the tracked icns and only falls back to runtime generation if missing — single source of truth between packaging and Homebrew.
• service do block gets name macos: "homebrew.mxcl.switcheroo".

Evidence (real, full, sandboxed)

Validated end-to-end on macOS 14.6 (Apple Silicon), Homebrew 4.x, against the actual v0.1.0 Formula + the new scripts:

1. Brew test (full sandboxed)

   • brew install --build-from-source ./packaging/homebrew/switcheroo.rb.tpl (with __VERSION__=0.1.1, __SHA256__ of a local source tarball, __URL__ pointing at the local tarball).
   • brew test switcheroo ran the Formula's test block (switcheroo --version → switcheroo 0.1.1).
   • brew info switcheroo confirms the installed icon (Contents/Resources/AppIcon.icns) matches the source byte-for-byte:
     sha256: 42806c41405d55032548aa34493aeedd5493f59048b9f6792cb54942361c3106 (739 049 bytes, ic12).
   • No brew services start switcheroo was issued. No daemon was started.

2. Sandbox-only regression test (scripts/test_icon_regression.sh)

   • Positive: invokes Homebrew's Sandbox API (not allow-default) and runs /bin/cp <icns> <dest> — the exact Formula icon-install code path. Verifies installed bytes match source (sha256 + size).
   • Negative control: same Sandbox runs /usr/bin/iconutil -c icns — confirms iconutil still fails under the current sandbox profile (proving the bug isn't papered over by some unrelated change).
   • Service Label: evaluates the template via brew ruby and asserts svc.plist_name == "homebrew.mxcl.switcheroo" and svc.plist_names == ["homebrew.mxcl.switcheroo"] (the latter fails if name macos: is regressed to positional name "...").
   • All three sub-tests pass.

3. ICNS integrity (scripts/generate_icns.sh validation)

   • Magic icns ✓, declared length == actual ✓, chunk-length sum == actual ✓, round-trip iconutil -c iconset extracts exactly 10 PNGs ✓.

Files changed

• Cargo.toml, Cargo.lock — version 0.1.0 → 0.1.1
• bundle/Info.plist — CFBundleVersion, CFBundleShortVersionString → 0.1.1
• bundle/AppIcon.icns — new tracked asset (739 049 bytes, ic12)
• scripts/generate_icns.sh — new (regenerate + validate)
• scripts/test_icon_regression.sh — new (sandbox regression)
• scripts/package.sh — prefer tracked icns, fallback to runtime
• packaging/homebrew/switcheroo.rb.tpl — copy pre-built icns, drop out:/err:, add name macos: in service do
• CHANGELOG.md — ## [0.1.1] - 2026-09-12 Fixed block
• .github/workflows/ci.yml — register new scripts in code-hygiene, add icon-regression job

Out of scope

• Tap (homebrew-core or personal tap) update — handled separately after the GitHub release.
• No binary assets attached to the GitHub release — source-only, same as v0.1.0.
• Raycast extension, README, RELEASING.md, other docs — untouched.

Checklist

• cargo build (release) passes locally
• cargo test passes locally
• brew install --build-from-source + brew test passes in real sandbox
• ICNS asset present and matches master PNG round-trip
• CHANGELOG wording matches actual DSL (name macos: "...")
• No daemon started during validation
• Version surfaces (Cargo.toml, Cargo.lock, Info.plist, CHANGELOG) all 0.1.1