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Debugging · Version 1.7.0 · Reviewed 2026-08-02

Android ANR Debugger

Diagnose main-thread stall analysis and binder wait diagnosis with evidence, explicit trade-offs, and a verification plan.

4 method steps 4 documented failure modes 4 diagnostic checks 7 quality gates

Diagnoses Application Not Responding incidents using main-thread traces, binder waits, lock contention, broadcast limits, and startup work.

₹99 one-time

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What this skill helps you do

  • Main-thread stall analysis
  • Binder wait diagnosis
  • Startup ANR investigation

How Android ANR Debugger works

You provide

Symptoms, timestamps, recent changes, and logs

It inspects

Correlated subset and first failing component for main-thread stall analysis

It decides

A ranked cause for binder wait diagnosis that explains recovery too

You verify

The cheapest discriminating test, run before the fix

What it checks first

Android ANR Debugger diagnoses Application Not Responding incidents using main-thread traces, binder waits, lock contention, broadcast limits, and startup work. Use it when the work involves Main-thread stall analysis, Binder wait diagnosis, Startup ANR investigation.

  1. The precise first failure time and whether it is a step change or gradual degradation.
  2. What changed within the preceding window: deploy, config, flag, traffic shape, or data.
  3. Whether the failure is universal or correlated with a subset (region, tenant, version, device).
  4. Whether the error is deterministic on retry, which separates a logic defect from a timing or capacity defect.

Failure modes it recognizes

  • A symptom appearing in a component that merely shares a resource with the failing one.
  • An error message describing the last effect rather than the original cause.
  • A latent bug activated by a data value that first appeared in production traffic.
  • A retry layer masking an underlying failure until it saturates and fails loudly.

Answers it will reject

  • Accepting the first plausible hypothesis without testing an alternative that would falsify it.
  • Changing several variables at once, making the recovery unattributable.
  • Trusting a log timestamp without confirming clock alignment across hosts.

Decision rules it applies

  • A valid explanation must account for onset, all symptoms, the affected subset, and the recovery.
  • Choose the test that eliminates the most hypotheses per unit of effort.
  • If nothing in the system changed, examine the inputs.

Evidence it asks for

  • Reconstruct a timestamped timeline from artifacts, not memory.
  • Break metrics down by dimension to isolate the correlated subset.
  • Reproduce in a controlled environment before attempting a fix.

The method inside

  1. Reconstruct the symptom timeline and define what healthy behavior would look like for main-thread stall analysis.
  2. Rank hypotheses for binder wait diagnosis by evidence, blast radius, and ability to explain every observed symptom.
  3. Run the cheapest discriminating check for Startup ANR investigation; update confidence only when evidence changes.
  4. Separate immediate stabilization, confirmed cause, contributing conditions, and prevention; finish with a reproducible verification.

Deliverables

  • Main-thread stall analysis assessment
  • Binder wait diagnosis decision and action plan
  • Startup ANR investigation verification checklist

Evidence requirements

  • Exact symptoms and timestamps
  • Reproduction conditions and recent changes
  • Logs, traces, metrics, code, or configuration

Quality gates

  • Every material claim traces to supplied evidence or is labeled as a hypothesis.
  • The response follows the declared deliverable contract.
  • No execution, access, measurement, or verification is invented.
  • Secrets and personal data are redacted rather than repeated.
  • The user receives a concrete independent verification step.
  • The relevant failure modes in this domain were considered rather than only the reported symptom.
  • No listed anti-pattern was recommended as a solution.

Example task

Input

Play Console shows input-dispatch ANRs, but CPU profiles do not reveal an obvious hot function.

Expected output

The main thread is blocked waiting for a synchronized cache while a worker performs disk I/O under the same lock. The issue is lock hold time, not CPU; separate disk access from the critical section...

Boundaries and compatibility

Ideal for

  • Main-thread stall analysis: produce a decision or artifact grounded in supplied evidence.
  • Binder wait diagnosis: produce a decision or artifact grounded in supplied evidence.
  • Startup ANR investigation: produce a decision or artifact grounded in supplied evidence.

Out of scope

  • Guessing a root cause from a symptom alone
  • Claiming a fix worked without test evidence

Agent compatibility

  • GitHub Copilot custom agents
  • Claude Agent Skills / SKILL.md
  • Any instruction-following chat model

Tool policy: Advisory by default. No tools are assumed. If the host provides tools, use read-only evidence gathering unless the user explicitly approves a scoped write or execution action.