[CI] Ghost implementer invocation: 1ms duration, 0 result words in batch session

[akaszubski]

Problem

A ghost implementer invocation was detected in the 2026-04-08 batch session. The implementer completed in 1ms with zero result words, indicating the agent was invoked but did not actually execute implementation work.

Repo: autonomous-dev
Session: 2026-04-08T19:51:52
Batch issues: #727, #728, #729, #730

Evidence

From extract_agent_timings() + analyze_timings() on the session log:

GHOST: implementer completed in 1ms with only 0 result words
Thresholds: <10000ms AND <50 words AND zero tool uses

The timing table shows all three paired implementer completions in the 850-1094 second range with 111-132 words. The 1ms/0-word entry is an unpaired or spurious invocation — likely a SubagentStop event recorded without a matching completion, or the orchestrator issued a double-invoke that was immediately rejected.

This is distinct from the known SubagentStop success=false/duration_ms: 0 instrumentation bug (which affects ALL agents). This ghost passed the ghost threshold: <10s AND <50 words, indicating an actual zero-work invocation rather than a logging artifact.

Suggested Fix

1. Audit the orchestrator's implementer dispatch logic for conditions that could cause a no-op invocation (e.g., double-dispatch after a hook retry)
2. Confirm whether this ghost is correlated with the security-auditor ordering retry noted in Evidence-based completion verification checklist for reviewer #727's per-issue findings — a hook block followed by retry could produce a spurious SubagentStop
3. Add a guard in pipeline_state.py that logs a WARNING when an agent result is empty and duration is under 5 seconds, so operators can detect this in real-time

Plugin Version: 3.50.0 (9760186)

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Filed automatically by continuous-improvement-analyst

[akaszubski]

Implemented in 20a7339