🧪 macOS 27 (Developer Preview) — issues & how to collect debug info

[ricardoleal]

TimeMachineTrimmer currently targets macOS 26 (Tahoe). macOS 27 is a pre-release and may introduce regressions in areas the app depends on: menu bar event dispatch, XPC/PrivilegedHelper communication, TCC/FDA enforcement, and tmutil behaviour.

Use this discussion to report any issues found on macOS 27. Please collect the info below before posting — it cuts investigation time significantly.

Note: Homebrew warnings about running a pre-release macOS during install are expected and harmless.

---

1. Environment

• macOS build: Settings → General → About → copy the full version string, e.g. 27.0 (26A5XXX)
• TimeMachineTrimmer version:
• Install method: .dmg / Homebrew tap
• Mac chip: Apple Silicon (M-series) or Intel

Quick version check:

defaults read /Applications/TimeMachineTrimmer.app/Contents/Info.plist CFBundleShortVersionString
defaults read /Applications/TimeMachineTrimmer.app/Contents/Info.plist CFBundleVersion

---

2. Runtime logs

Run this before reproducing the issue, then paste the output:

log stream --predicate 'process == "TimeMachineTrimmer" OR process == "com.ricardoleal.TimeMachineTrimmer.Helper"' --level debug

The filter covers both the main app and the PrivilegedHelper, which handles the actual tmutil operations.

---

3. PrivilegedHelper status

The app uses a privileged helper tool (com.ricardoleal.TimeMachineTrimmer.Helper) registered with launchd via SMJobBless. If this isn't running, nothing works.

Check whether it's installed and running:

sudo launchctl list | grep -i timemachine

Check for its LaunchDaemon plist:

ls -la /Library/LaunchDaemons/ | grep -i timemachine

If found, read its content:

sudo plutil -p /Library/LaunchDaemons/com.ricardoleal.TimeMachineTrimmer.Helper.plist

Check whether the helper binary is installed:

ls -la /Library/PrivilegedHelperTools/ | grep -i timemachine

---

4. App bundle Info.plist

Share the full content of the app's Info.plist — useful to verify entitlements and bundle identifiers are intact after install:

plutil -p /Applications/TimeMachineTrimmer.app/Contents/Info.plist

And for the PrivilegedHelper embedded plist (if accessible):

plutil -p /Applications/TimeMachineTrimmer.app/Contents/Library/LaunchServices/com.ricardoleal.TimeMachineTrimmer.Helper

---

5. Full Disk Access (FDA)

The app requires FDA to read /Library/Preferences/com.apple.TimeMachine.plist and list backups. Without it, operations silently fail.

Check whether the app appears in Privacy & Security:

sudo sqlite3 /Library/Application\ Support/com.apple.TCC/TCC.db \
  "SELECT client, auth_value, auth_reason FROM access WHERE service='kTCCServiceSystemPolicyAllFiles';" 2>/dev/null

Look for com.ricardoleal.TimeMachineTrimmer and com.ricardoleal.TimeMachineTrimmer.Helper in the output.

Also confirm whether the system TimeMachine plist is readable at all:

cat /Library/Preferences/com.apple.TimeMachine.plist > /dev/null && echo "FDA OK" || echo "FDA missing or denied"

If FDA is stuck or was never prompted, reset and re-grant:

tccutil reset SystemPolicyAllFiles com.ricardoleal.TimeMachineTrimmer

⚠️ This resets FDA for the app only. macOS will re-prompt on next launch.

---

6. App preferences plist

plutil -p ~/Library/Preferences/com.ricardoleal.TimeMachineTrimmer.plist

If the file doesn't exist, mention it — it means the app never successfully wrote its defaults.

---

7. Crash reports

ls -lt ~/Library/Logs/DiagnosticReports/ | grep -i TimeMachine | head -5

Open the most recent .ips or .crash file and paste the first 60 lines. Also check Console.app → Crash Reports.

---

8. tmutil sanity check

Confirms whether the issue is at the app layer or the system layer:

tmutil status
tmutil listbackups 2>&1 | head -20

---

Issue report template

**macOS version + build:** (e.g. 27.0 26A5XXX)
**TimeMachineTrimmer version:**
**Install method:** dmg / Homebrew
**Mac chip:** Apple Silicon / Intel

**What happened:**

**Steps to reproduce:**
1.
2.
3.

**Expected behaviour:**

**Actual behaviour:**

**Runtime logs** (both processes):
(output of: log stream --predicate 'process == "TimeMachineTrimmer" OR process == "com.ricardoleal.TimeMachineTrimmer.Helper"' --level debug)

**PrivilegedHelper status:**
(output of: sudo launchctl list | grep -i timemachine)

**FDA check:**
(output of the TCC.db sqlite3 query above, or "FDA OK" / "FDA missing")

**App Info.plist:**
(output of: plutil -p /Applications/TimeMachineTrimmer.app/Contents/Info.plist)

**Preferences plist:**
(output of: plutil -p ~/Library/Preferences/com.ricardoleal.TimeMachineTrimmer.plist)

**Crash report (if any):**
(first 60 lines of the .ips/.crash file)

[mjbeckernc]

TimeMachineTrimmer.txt