ADR 0204: Explicit Unsigned macOS First-Launch Helper

• Status: Superseded for macOS distribution by D634 / ADR 0309
• Date: 2026-09-09
• Deciders: Nib core
• Related: D078, D371, D406, D450, D457, D634, E2E-196b, ADR 0289, ADR 0296, ADR 0309

Context

Local and debug macOS packaging remain unsigned so contributors and release operators can build without Developer ID credentials. A trusted download of that artifact can still carry Apple's quarantine attribute, which may make Gatekeeper report that Nib is damaged. The existing guidance required users to open Terminal and run xattr -cr, which is broader than the single attribute that causes this launch failure.

Decision

1. Every macOS distribution includes an executable Nib-macOS-open.command alongside the opening-help note. The DMG places the helper in a visible first-launch row below the install gesture.
2. The helper searches only /Applications/Nib.app and ~/Applications/Nib.app. It verifies the bundle identifier is net.aiuo.pi-desktop, and the user must move the app into one of those directories before running it.
3. When the verified app carries com.apple.quarantine, the helper recursively removes only that attribute and then opens Nib. It never uses sudo, accepts no arbitrary path argument, removes no other extended attribute, and does not claim that an unsigned app passed Gatekeeper qualification.
4. The DMG labels the package as unsigned and the note continues to state that signed and notarized builds do not need the helper.
5. Developer ID signing and notarization remain the release path for normal Gatekeeper launches; this helper is an explicit user action for trusted unsigned artifacts, not a replacement for signing.

Consequences

• A user can read the documented unsigned first-launch fallback from the DMG; the ZIP retains the one-Finder-double-click helper after the normal drag-to-Applications step.
• Other extended attributes remain intact, reducing the scope of the quarantine workaround.
• The helper cannot repair an app installed outside the two standard Applications directories; the opening note provides the supported Terminal fallback for /Applications.
• The same helper is harmless in signed packages but is not needed there.

Amendment (D406 / ADR 0232)

The DMG-specific helper placement is replaced. DMGs now expose only the opening-help note, displayed as If app won't open, read this.txt; the executable helper remains in the macOS ZIP package. The note is the DMG fallback and no longer describes a helper that is present in the DMG.

Alternatives considered

• Keep the Terminal-only xattr -cr instruction: rejected because it is not a one-click flow and clears more metadata than necessary.
• Use sudo or target a user-selected arbitrary path: rejected because it would expand the privilege and application scope of an installer workaround.
• Require signing for every local build: rejected because D078 intentionally keeps local packaging available without Developer ID credentials.

Amendment (D450 / ADR 0289)

Official GitHub tag releases are Developer ID-signed and notarized. The first-launch helper and opening note remain for trusted unsigned local or debug artifacts only. Official Release DMGs must not claim they are unsigned.

Amendment (D457 / ADR 0296)

The DMG no longer shows the opening-help note. ZIP retains the helper and note for trusted unsigned local or debug artifacts.