Xcode Sync

Xcode Sync

Synchronize exact Xcode builds across Peter's supported Macs. Use $remote-mac for fleet topology and SSH rules.

Inventory

1. Read ~/Projects/manager/computers.yaml; use live tailscale status --json for reachability/IPs.
2. Exclude handed-off and unknown hosts. Verify hostname, user, macOS, architecture, and hardware UUID before writes.
3. Deduplicate Tailscale nodes by hardware UUID; one Mac may have multiple live node records.
4. Run scripts/xcode-host-inventory.sh locally or remotely:

skills/xcode-sync/scripts/xcode-host-inventory.sh
ssh -o RequestTTY=no -o RemoteCommand=none HOST 'bash -s' \
  < skills/xcode-sync/scripts/xcode-host-inventory.sh

Treat unreachable hosts as pending, not synchronized. Try live Tailscale IP, Tailscale SSH, then mDNS/LAN only when network topology permits.

Simulator hygiene

Every fleet Mac must pass the simulator-hygiene audit, including worker Macs where the correct result is not-applicable because Xcode and simctl are absent. Apple CoreSimulator's own classifications are authoritative: remove runtime images reported by simctl runtime delete --outdated --dry-run or --unusable --dry-run, plus simulator devices attached to unavailable runtimes. Do not classify a runtime as stale from its version number alone; stable and beta Xcodes can legitimately need different runtime generations on the same Mac.

Run the dependency-light audit locally or stream it to a remote Mac:

skills/xcode-sync/scripts/xcode-simulator-hygiene.sh
ssh -o RequestTTY=no -o RemoteCommand=none HOST 'bash -s' \
  < skills/xcode-sync/scripts/xcode-simulator-hygiene.sh

The audit exits 1 for drift. After verifying the host identity and current Xcode work, repair with --repair; the action deletes unavailable devices and Apple's outdated/unusable runtime candidates, then re-audits. It refuses repair while a simulator device is booted. Do not use age-based runtime deletion, --notUsedSinceDays, or all for routine fleet maintenance.

Inspect source

Prefer the user's downloaded .xip; do not redownload it.

pkgutil --check-signature "$archive"
shasum -a 256 "$archive"
stage=$(mktemp -d /tmp/xcode.XXXXXX)
cleanup() { rm -rf "$stage"; }
trap cleanup EXIT
(cd "$stage" && xip --expand "$archive")
set -- "$stage"/Xcode*.app
[[ $# == 1 && -d "$1" ]]
app=$1
plutil -extract CFBundleShortVersionString raw -o - "$app/Contents/Info.plist"
plutil -extract ProductBuildVersion raw -o - "$app/Contents/version.plist"
plutil -extract LSMinimumSystemVersion raw -o - "$app/Contents/Info.plist"
DEVELOPER_DIR="$app/Contents/Developer" xcodebuild -version
cleanup
trap - EXIT

Require Apple Software signature. Compare ProductBuildVersion, not version label alone: two archives named Xcode 26.6 may contain different builds. Do not use DTXcodeBuild as the sync key; it can differ from the build reported by xcodebuild -version.

Compatibility

• Require Apple silicon for an Apple-silicon-only archive.
• Require host macOS >= LSMinimumSystemVersion.
• Fleet rule: install Xcode 26.6 only on macOS 26 Tahoe, version 26.2 or newer. Skip macOS 27 Golden Gate even if the bundle launches.
• Apply explicit user exclusions after technical checks.

Never change a host OS to make an Xcode build eligible unless explicitly requested.

Transfer and install

1. Transfer the signed archive, not an expanded app; preserve resumability:

rsync -a --partial --progress -e 'ssh -o RequestTTY=no -o RemoteCommand=none' \
  "$archive" HOST:Downloads/

2. Verify the remote SHA-256 and signature before expansion.
3. Expand on the destination. Use a single-quoted remote script or ssh HOST 'bash -s'; never let the local shell expand remote $variables or $(commands).
4. Keep this app policy:
   • current stable: /Applications/Xcode.app
   • newest prerelease, beta or RC: /Applications/Xcode-beta.app
   • previous-major stable: /Applications/Xcode-previous.app, only for three months after a new stable major ships unless the user sets another window
5. Replace same-major point releases and same-channel prereleases; do not preserve them. An RC replaces the beta slot. Validate the staged app, move the old app to a temporary rollback path, install and verify the new app, then delete the rollback copy. Restore the old app on failure.
6. When stable advances to a new major, rotate transactionally: move any existing Xcode-previous.app to a temporary rollback path, move the former stable to Xcode-previous.app, install and verify the new stable, then delete the older rollback copy. Restore both channel paths on failure. Record the new previous-major removal date in the task report.
7. Stop on unexpected destination collisions. Never delete an app outside these known channels without explicit confirmation.
8. Preserve xcode-select unless the user requests a switch. Replacing the app at the already-selected path preserves selection.

Use writable /Applications directly. Otherwise use passwordless sudo -n; if admin approval is required, show a local macOS authorization prompt or report the exact pending step. Do not bypass receipts or license state.

First launch and verification

For every installed app:

DEVELOPER_DIR="$app/Contents/Developer" xcodebuild -version
codesign --verify --deep --strict "$app"
DEVELOPER_DIR="$app/Contents/Developer" xcodebuild -checkFirstLaunchStatus

If first-launch status is nonzero:

sudo env DEVELOPER_DIR="$app/Contents/Developer" xcodebuild -license accept
sudo env DEVELOPER_DIR="$app/Contents/Developer" xcodebuild -runFirstLaunch

Recheck until status 0. If sudo/admin UI is unavailable, the app is installed but not ready; report that distinction.

Finish with a host matrix: macOS, desired version/build, installed path, selected path, signature, first-launch state, simulator-hygiene state, previous-major removal date, and skip/failure reason. Keep source archives unless deletion is explicitly requested.