Verified as of 2026-07 — content assumes macOS 13 (Ventura) and later (
.ipspanic format on macOS 12+, universal SSH on macOS 13+).
Helps with
Slow Mac, silent drive failure, unexplained panics, TCC denials, a full disk, 3am wakes, runaway system daemons, login loops, safe eject, failing-drive cloning, remote and Apple Silicon diagnostics. Where each signal lives: references/symptom-guide.md.
The Universal Insight
macOS tells you what's wrong if you ask the right log in the right way. Most users (and most tutorials) reach for Activity Monitor or "About This Mac". The actual diagnostic signal lives in log show (the unified logging system), in /Library/Logs/DiagnosticReports/, in pmset -g log, in the TCC databases, and in launchctl print. This skill packages the queries that turn noise into a verdict.
The most common diagnostic failure: treating symptoms in isolation. "Slow boot" → disable login items. "Kernel panic" → reinstall macOS. "Random freezes" → reset SMC/NVRAM. These are reasonable last resorts, but the data to identify the actual cause is sitting in the unified log untouched. Always audit before treating.
The Diagnostic Ladder
Walk down the layers in order. Each rung has a binary outcome:
1. Hardware health — pmset, SMC errors, thermal events, Secure Enclave
2. Storage health — APFS state, IO errors, snapshot bloat
3. Panic record — DiagnosticReports/*.{panic,ips} + kext provenance
4. Pre-panic timeline — log show last 10 minutes before each panic
5. Startup inventory — Login Items + LaunchAgents + LaunchDaemons + profiles
6. Resource pressure — top CPU/mem, mds_stores, photoanalysisd, cloudd
7. Permissions / TCC — what app is denied what (the macOS-unique rung)
8. Verdict — what's failing, what to do
The most interesting failures cluster at rungs 2 (storage), 5 (startup bloat), and 7 (TCC denials). The least interesting (but most-treated) is rung 6.
Workflow
1. Run the comprehensive audit
scripts/health-audit.sh
Produces a verdict block: hardware events, storage health per volume, recent panics, top resource consumers, startup inventory, TCC denials. Scan for [FAIL] markers — that's where to drill.
2. Drill into the failing layer
| Symptom | Script |
|---|---|
| Storage errors flagged | scripts/disk-health.sh -v /Volumes/X (or -d disk2) — focused per-volume deep dive: APFS state, IO errors, snapshot bloat, verdict |
| Recent panic | scripts/panic-triage.sh (latest by default) or -f /Library/Logs/DiagnosticReports/Kernel_*.panic — kext + pre-panic timeline |
| "Is it safe to eject volume X?" | scripts/drive-dependencies.sh -v /Volumes/X — open files, Spotlight index, TM target, Photos lib, helper-tool bookmarks |
| "Why is boot taking so long?" | scripts/boot-perf.sh — per-boot durations from log show, with slow-component flags |
| App can't see screen/mic/files | scripts/tcc-audit.sh -a <bundle-id-or-name> — what TCC has granted, what's been denied recently |
| Mac waking at night | scripts/wake-reasons.sh — pmset log breakdown by reason class |
| Spotlight broken / mds CPU spike | scripts/spotlight-status.sh — index state per volume, common fixes |
| Storage "full" but disk usage doesn't add up | scripts/storage-pressure.sh — APFS snapshots, local Time Machine, purgeable bytes |
| Kernel panic blames a kext / loaded kext audit | scripts/kext-audit.sh — third-party kexts + system extensions + SIP/security policy state |
| Firewall behavior / VPN tunnel inventory | scripts/firewall-audit.sh — ALF + pf + Network Extension content filters + utun inventory |
| Network preferences across location profiles | scripts/network-locations.sh — DNS / proxy / search domains per location, service order |
3. Apply the minimum reversible fix
| Action | Script |
|---|---|
| Disable startup item by name | scripts/safe-disable-startup.sh -n <pattern> — works across Login Items + LaunchAgents (no sudo for user-scope) |
| List current state of all startup entries | scripts/safe-disable-startup.sh --list |
| Re-enable previously disabled | scripts/safe-disable-startup.sh -n <pattern> --enable |
| Disable system-scope daemon (admin) | sudo launchctl disable system/<label> then sudo launchctl bootout system/<label> |
| Reset TCC for a specific service+bundle | tccutil reset <Service> <bundle-id> (per-service, not global) |
| Safe clone from failing drive | scripts/recover-clone.sh -s <source> -d <destination> — rsync --partial --inplace --no-whole-file |
All disables are reversible — Login Items via osascript System Events, LaunchAgents via launchctl disable. The inverse re-enables.
Storage Health & Failure Detection
The highest-yield audit. Failing drives cause slow boots (kernel waits on probe timeouts), instability (IO retries cascade into kernel hangs), and panics (paging failures kill WindowServer). Three independent data sources to cross-reference:
IO error events
log show --last 30d --style compact \
--predicate 'subsystem == "com.apple.iokit" AND (eventMessage CONTAINS "I/O error" OR eventMessage CONTAINS "media error")' \
2>/dev/null | head -30
Healthy drives produce zero of these per month. Dozens = active failure regardless of what "About This Mac → Storage" claims.
APFS health
diskutil apfs list
diskutil apfs verifyVolume / # READ-ONLY — does not write
Look for Verify failed per-volume, container free-space mismatches, or snapshot trees growing without bound.
SMART status (via vendor / smartmontools)
macOS's built-in SMART status (diskutil info /dev/diskN) reports only Verified or Failing. For real attributes, install smartmontools (brew install smartmontools) and use smartctl -a /dev/diskN. NVMe drives often return blank — fall back to vendor tools or the per-vendor utilities.
Disk → volume mapping
diskutil list
diskutil info disk2s1
Cross-reference with df -h for mount point.
Boot Performance & Startup Management
macOS has four primary startup mechanisms, each requiring different tooling. System Settings only shows one of them (Login Items). Full inventory in references/startup-mechanisms.md.
| Mechanism | Where | How to inspect | How to disable |
|---|---|---|---|
| Login Items | System Settings → General → Login Items | osascript System Events |
osascript (no sudo) |
| User LaunchAgents | ~/Library/LaunchAgents/*.plist |
launchctl print gui/$UID |
launchctl disable gui/$UID/<label> |
| System LaunchAgents (per-user) | /Library/LaunchAgents/*.plist |
launchctl print gui/$UID |
launchctl disable gui/$UID/<label> (no sudo for current user) |
| System LaunchDaemons | /Library/LaunchDaemons/*.plist |
sudo launchctl print system |
sudo launchctl disable system/<label> |
| (Legacy) LoginHook | com.apple.loginwindow LoginHook key |
sudo defaults read com.apple.loginwindow LoginHook |
sudo defaults delete com.apple.loginwindow LoginHook |
launchctl disable vs bootout
| Command | Effect |
|---|---|
launchctl disable <domain>/<label> |
Persistently disabled across reboots. Reversible with enable. |
launchctl bootout <domain>/<label> |
Unloads the running service NOW. Comes back on next reboot if not also disabled. |
launchctl unload <plist> |
Legacy form. Avoid in new scripts. |
The right pair for "kill this daemon permanently": disable then bootout. The script scripts/safe-disable-startup.sh does both.
Boot duration measurement
macOS records boot timing in the unified log. Approximate via:
log show --last 1h --style compact \
--predicate 'eventMessage CONTAINS "BOOT_TIME" OR eventMessage CONTAINS "loginwindow"' \
| head -50
Healthy Apple Silicon Mac: 10-20s to login screen. Intel Mac with spinning disk (vintage 2015 Mini): 25-45s. Failing storage: 60+s with stalls.
Panic Analysis & Diagnostic Reports
Where panics live
/Library/Logs/DiagnosticReports/*.panic (legacy Intel + early Apple Silicon)
/Library/Logs/DiagnosticReports/*.ips (modern format, all panics on macOS 12+)
~/Library/Logs/DiagnosticReports/ (per-user crashes, not panics)
.ips files are JSON. The .panic files are plain text but follow a strict structure.
Anatomy of a panic report
panic(cpu N caller 0x...): "Sleep wake failure in EFI"
Loaded kexts:
com.apple.driver.AppleEFIRuntime ...
com.eltima.ProductX 2.1.7 <— third-party suspect
...
The kext list is the most actionable signal. A panic that loaded only Apple kexts is harder to fix than one with a clear third-party suspect — kext-extraction-and-removal is the first move.
Common panic strings (full catalog in references/panic-codes.md)
| String fragment | Likely cause |
|---|---|
| "Sleep wake failure" | Driver hung during S3/S4 transition (often USB, Bluetooth, GPU) |
| "Unable to find driver" | Boot-time kext load failure — likely after macOS update |
| "Unresponsive bootstrap subsystem" | launchd deadlock — usually third-party LaunchDaemon |
| "WindowServer panic" | GPU driver or display kext fault |
| "double_fault" / "page_fault" | Kernel-mode memory corruption — kext bug or RAM fault |
| "panic_kthread" | Kernel watchdog timeout — driver in infinite loop |
Pre-panic timeline
The panic record alone rarely tells you the cause. The events in the 10 minutes before are where the story is:
scripts/panic-triage.sh -t '2026-05-15 03:14:22' -m 10
Look for:
- Disk arbitration errors before panic → storage failure cascade
kernelwarnings naming a third-party kext before panic → driver hangpowerd/assertionmessages before sleep panic → pmset assertion held by misbehaving app
TCC (Privacy Permissions) Audit
A macOS-unique diagnostic layer. The TCC databases at:
/Library/Application Support/com.apple.TCC/TCC.db (system, requires sudo)
~/Library/Application Support/com.apple.TCC/TCC.db (per-user)
…store every "Allow / Deny" grant ever made. Reading them tells you exactly which app has Screen Recording, Camera, Microphone, Full Disk Access, Accessibility, Automation, etc. — and which apps have been denied recently (the most common "this app doesn't work" cause).
Full schema and reset procedures in references/tcc-mechanics.md. The scripts/tcc-audit.sh script wraps the common queries.
Common Failure Modes
| Symptom | First check | Common cause |
|---|---|---|
| Slow boot, used to be fast | startup-audit.sh |
Login Item / LaunchAgent bloat (Adobe CC, Docker, Setapp) |
| Slow boot, getting worse | disk-health.sh |
Failing SSD — APFS retries inflating boot time |
| Random freezes + hard restart | disk-health.sh + panic-triage.sh |
IO errors cascading into kernel hang |
| Kernel panic on wake | panic-triage.sh (look for "Sleep wake failure") |
Driver power-state bug (often USB, GPU, Bluetooth) |
| App can't access screen/mic | tcc-audit.sh -a <app> |
TCC denial, often from a recent system update |
| "Macintosh HD almost full" | storage-pressure.sh |
Local Time Machine snapshots + purgeable cache |
| Mac wakes at 3am | wake-reasons.sh |
Scheduled maintenance, BT keyboard tap, or kext bug |
mds_stores CPU 100% |
spotlight-status.sh |
Reindex on volume with no on-disk index store |
| Login loop / gray screen | recoveryOS + safe boot + this skill's recovery docs | Bad LaunchAgent, corrupt Login Items, kext panic at boot |
Recovery Patterns
Failing-drive data recovery
Never fsck_apfs -y a failing drive — -y answers Yes to repairs, which writes back. Use fsck_apfs -n (verify-only) first. Image first, repair the image second.
# Safe clone with no retries (skips bad sectors fast)
rsync -avh --partial --inplace --no-whole-file --append-verify \
/Volumes/Failing/important/ /Volumes/Rescue/important/
For bit-level recovery, install gddrescue via Homebrew and use a map file so the operation is resumable. Documented in references/recovery-patterns.md.
Physically removing a failing drive
If a drive is causing boot stalls or panics:
- Identify via
disk-health.sh - Verify nothing critical points at it (
drive-dependencies.sh -v /Volumes/X) diskutil unmount /Volumes/X(ordiskutil eject /dev/diskNfor the whole device)- Physically disconnect / power down before remount attempts
Voice & Output Style
Output follows the claude-mods diagnostic convention:
[PASS]/[FAIL]/[WARN]/[INFO]prefixes for scan rows- Verdict block at the bottom with specific findings + recommended actions
- Volume identifications include disk identifier, mount point, APFS role
- Panic references include UTC timestamp, panic string, primary suspect kext
- Panel rendering via
skills/_lib/term.shwhen a TTY is present; raw text otherwise --jsonemits NDJSON for piping;--redactmasks private addrs / hostnames / serial numbers
What This Skill Doesn't Cover
- Network diagnostics → use
net-ops - Windows-side workstation issues → use
windows-ops - Specific application performance profiling → use
perf-ops - Source-code-level debugging → use
debug-ops - iOS / iPadOS device issues — different platform
- MDM authoring (creating configuration profiles) — out of scope; we read them, not author them
Cross-References
| When | Use |
|---|---|
| Triaging a remote Mac | net-ops/ssh-bootstrap.sh to land, then this skill's scripts |
| Panic blames a network kext | Combine with net-ops for VPN/DNS interactions |
| Same pattern on multiple Macs | Run health-audit.sh --json on each, diff outputs |
| Suspect Windows + Mac in same household | windows-ops + mac-ops, same conventions |
References
-
references/storage-events.md— IO error patterns in unified log, APFS-specific event vocabulary, disk arbitration messages. Load when investigating volume errors or correlating IO failures to a specific device. -
references/panic-codes.md— Common kernel panic strings, kext-extraction patterns, Apple Silicon vs Intel panic format differences. Load when decoding a non-trivial.panic/.ipsfile or matching a symptom to a likely cause. -
references/startup-mechanisms.md— Deep dive on Login Items, LaunchAgents (user + system), LaunchDaemons, legacy LoginHook, configuration profile login items. Load when doing a full startup audit or hunting vendor-installed auto-launch hooks. -
references/recovery-patterns.md— Failing-drive recovery (rsync, gddrescue), APFS snapshot rollback, target disk mode, recoveryOS, single-user mode on Apple Silicon vs Intel. Load when responding to "my drive is dying" or any destructive operation. -
references/remote-diagnostics.md— SSH staging pattern (scp -r mac-ops/ remote:),kickstartfor enabling ARD, sudo over SSH considerations. Load when troubleshooting "my parents' Mac across town". -
references/tcc-mechanics.md— How TCC works under the hood. Both TCC.db locations, "service" string catalog (kTCCServiceScreenCapture, kTCCServiceAccessibility, etc.), grant types, when to usetccutil resetvs editing the DB, SIP interaction. Load when an app silently fails to access screen / mic / files. -
references/launchd-deep-dive.md— launchd plist semantics,RunAtLoadvsKeepAlive,ThrottleInterval, why daemons fail to load,disablevsbootoutvsunload, domain targets (system, user, gui), and Apple Silicon specifics (system extensions replacing kexts). -
references/symptom-guide.md— Symptom-by-symptom index: what each complaint usually is, which log or database holds its signal, and the misleading first instinct. Load when a report is vague and you need the starting rung.
Worked example
A 3am-wake, slow-by-day Mac taken end to end through the health-audit.sh panel and the drill-down scripts, with the full command sequence: references/worked-examples.md.