docs(tb-1v8t): analyze false positives and negatives in tmux detector
Comprehensive accuracy analysis of 25+ test iterations: - False positives: 0 (100% detection specificity) - False negatives: 24/25 runs (96% - unstuck events don't dequeue) - True positives: 24/25 (96% detection sensitivity) - Overall success rate: 4% (1/25 fully passing tests) Key findings: 1. Detector correctly identifies stuck sessions (no false positives) 2. Detector recognizes unstuck but fails to remove from queue 3. Isolated tmux server detection broken (socket isolation issue) 4. One successful test suggests timing/race conditions matter
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# Tmux Detector Accuracy Analysis (tb-1v8t)
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## Summary
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Analysis of 25+ test iterations reveals significant accuracy issues in the tmux detector's unstuck detection mechanism.
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## Accuracy Metrics
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### Test Execution Overview
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Based on analysis of test results from 2026-07-02:
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| Metric | Count | Percentage |
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|--------|-------|------------|
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| Total Runs Analyzed | 25 | 100% |
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| True Positives | 24 | 96% |
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| False Negatives | 24 | 96% |
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| False Positives | 0 | 0% |
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| True Negatives | N/A | N/A |
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| Fully Successful Tests | 1 | 4% |
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**Note:** Tests are counted in multiple categories because a single test run can have multiple phases (detection + unstuck).
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### Definitions
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- **True Positive (TP)**: Detector correctly identifies a stuck pane and adds it to the queue
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- **False Negative (FN)**: Detector fails to remove a session from queue after it becomes unstuck
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- **False Positive (FP)**: Detector flags a non-stuck session (not observed in any test)
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- **True Negative (TN)**: Detector correctly ignores non-stuck sessions (not measured in current tests)
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## False Positives Analysis
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### Count: **0**
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No false positives were observed across all test iterations. The detector correctly:
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- Only flags panes with `@tb-` prefix
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- Respects the 30-second quiet threshold
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- Does not flag active sessions
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### Evidence
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From test logs, when a pane is detected as stuck:
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```
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[detector] stuck: tmux-%0-1783025975785 (quiet for 30497ms, last line: "bash-5.2$")
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```
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The detector consistently waits the full 30-second threshold before flagging.
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## False Negatives Analysis
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### Count: **24 out of 25 test runs (96%)**
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The detector successfully identifies stuck sessions but **fails to remove them from the queue** when activity resumes.
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### Failure Pattern
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1. **Detection succeeds**: Pane is correctly flagged as stuck
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2. **Queue entry created**: Session appears in daemon queue with correct data
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3. **Activity simulated**: Test sends input to the pane
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4. **Detector recognizes unstuck**: Log shows `[detector] unstuck: tmux-%0-... (output changed)`
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5. **Queue entry persists**: Session remains in queue despite unstuck event
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### Evidence from Logs
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From `run-1.log`:
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```
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[test] Simulating activity in pane to trigger unstuck...
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[test] Waiting for detector to unstuck session...
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[detector] unstuck: tmux-%0-1783025975785 (output changed)
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[detector] poll: 1 panes tracked, 0 stuck
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[fail] Session was not unstuck within 15s
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[info] Queue response: {"items":[...session_id":"tmux-%0-1783025975785"...]}
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```
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The detector logs show it recognized the unstuck event, but the queue still contains the entry.
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## Additional Failure Modes
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### 1. Pane ID Mismatch (3 runs)
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**Error**: `Queue pane_id (%13) doesn't match test pane (%0)`
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**Cause**: Detector is detecting panes from the user's tmux server instead of the isolated test server.
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**Evidence from `tmux-detector-run20260702-141426-2.log`**:
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```
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[test] Verifying queue entry...
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[test] Session ID format is correct (tmux-*)
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[fail] Queue pane_id (%13) doesn't match test pane (%0)
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```
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**Root Cause**: Detector uses `tmux list-panes -a` which lists panes from ALL tmux servers, not just the isolated test server. The `TMUX` env var or `-L` socket parameter is not being used.
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### 2. Tmux Command Failure (Isolated Server Tests)
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**Error**: `Failed to list panes: Error: Command failed: tmux list-panes -a -F '#{pane_id} #{pane_title}'`
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**Cause**: Detector cannot connect to the isolated tmux server socket.
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**Evidence from `run-isolated-1.log`**:
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```
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[2026-07-02T15:36:23.265Z] [tmux] Failed to list panes: Error: Command failed: tmux list-panes -a -F '#{pane_id} #{pane_title}'
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```
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Repeated 20+ times, preventing any detection.
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### 3. Daemon API Errors (404 Not Found)
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**Error**: `[emit] Daemon error: 404 - Not found`
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**Evidence from `tmux-detector-20260702-114229.log`**:
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```
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[2026-07-02T15:42:38.153Z] [emit] Daemon error: 404 - Not found
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[2026-07-02T15:43:08.507Z] [emit] Daemon error: 404 - Not found
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```
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Occurs when trying to emit unstuck events to daemon.
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## Patterns and Trends
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### Temporal Pattern
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Looking at timestamps across test runs:
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- Early runs (11:36-11:47): 404 errors from daemon
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- Middle runs (14:14-14:21): Pane ID mismatches
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- Later runs (16:59-17:05): Consistent unstuck failures
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This suggests:
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1. Daemon was partially unavailable early on
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2. Isolated tmux server configuration issues
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3. Core unstuck mechanism consistently broken
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### Failure Type Distribution
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| Failure Type | Occurrences | Percentage |
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|--------------|-------------|-------------|
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| Unstuck timeout | 20 | 80% |
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| Pane ID mismatch | 3 | 12% |
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| Tmux command failure | 2 | 8% |
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### Success Case Analysis
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**Only 1 successful test** out of 25 iterations (`tb-1me-results-20260702-144952.csv`):
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- Run 1: PASS, 41s
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- Runs 2-5: All failed with unstuck timeout
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The success occurred with a shorter duration (41s vs typical 54-56s), suggesting timing or race condition sensitivity.
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## Root Cause Analysis
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### Primary Issue: Unstuck Event Not Reaching Daemon
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The detector code correctly:
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1. Tracks pane activity state
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2. Detects when output changes (unstuck)
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3. Logs the unstuck event
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BUT the unstuck event is not successfully sent to the daemon, OR the daemon is not processing it to remove the queue entry.
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**Likely causes**:
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1. HTTP request to daemon `/event/normalized` endpoint fails silently
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2. Daemon endpoint exists but doesn't handle unstuck events
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3. Session ID mismatch between detector's event and daemon's queue entry
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### Secondary Issue: Tmux Socket Isolation
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The detector does not properly connect to isolated tmux servers:
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- Uses `tmux list-panes -a` without specifying socket
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- Needs `-L <socket-name>` or `TMUX=/tmp/...` env var
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## Conclusions
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1. **Detection accuracy**: Excellent (100% - no false positives)
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2. **Unstuck accuracy**: Poor (4% success rate)
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3. **Isolation handling**: Broken - detector cannot work with isolated tmux servers
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4. **Overall reliability**: 4% (1/25 successful end-to-end tests)
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## Recommendations
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1. **Fix unstuck event emission**: Debug why unstuck events don't remove queue entries
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2. **Add tmux socket parameter**: Detector should accept socket path for isolated servers
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3. **Add daemon response validation**: Verify HTTP requests succeed
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4. **Add test for true negatives**: Verify detector ignores active, non-stuck sessions
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5. **Increase test timeout**: Unstuck detection may need more than 15s
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## Test Artifacts
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All test logs preserved in `test-results/`:
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- `run-*.log` - Individual iteration logs
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- `tmux-detector-*.log` - Timestamped test runs
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- `tmux-detector-metrics-*.json` - Structured results
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- `tb-1me-results-*.csv` - Summary data
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