# #1512 inherited engine diagnosis

Rocko returned a read-only investigation. No source correction, live connector
operation or authority transfer follows from it. Filbert's seven source pins
remain the #1512 candidate; they do not change Discord engine code.

## A. Test synchronization and cleanup

Rocko reports the tool-turn test asserts engine.busy immediately after prompt
resolution at agent_end, while busy clears on a subsequent agent_settled event.
Separate pipe reads allow the assertion to run between events. Another basic
prompt test uses the same assumption. Success-only engine.stop cleanup leaves
the fake child and pipes open after an assertion fails, hiding the final spec
report and making the test file hang.

Darkwing independently ran Rocko's scratch relay with DELAY=50 and finally cleanup.
It failed 'busy after plain resolved', true versus false, and exited in 148ms.
Log: /tmp/darkwing-1512-race-confirmation.txt. This confirms the race mechanism,
not the exact historical assertion from the earlier truncated spec log.

Rocko's scratch directory:
/tmp/claude-1000/-mnt-storage-src-mosaic-stack/0422f20f-4d8c-43fe-b429-a2730cc1ab9d/scratchpad/1512/
Includes proxy-pi.mjs, race-repro.test.mjs, hang-repro.test.mjs,
hang-noforce.txt, hang-force.txt and stress/base-prev run logs.
He reports natural busy failures at lines56/75 under contention and deterministic
hang behavior without finally cleanup. Darkwing did not repeat load stress.

## B. Timeout test synchronization

Rocko reports a 100ms timeout test reads fake-pi's command log before the child
has created it or recorded abort under contention. That assertion can also skip
success-only cleanup. He observed this in both prior and row21 code. Not the
specific failed test named in Darkwing's first run.

## C. Separate engine behavior concern

Rocko reports a next-prompt refusal after a client timeout when a done pending
entry remains, busy is false and agent_start has not yet been consumed. prompt()
then omits followUp because it considers only pending entries not marked done.
The still-streaming fake engine refuses that prompt. This is a potential real
engine defect, not merely the busy assertion race. No live incident is established.

The row21 owner retains this code. Darkwing notified orch-01 on its verified named
socket and requested ownership/disposition, not a code takeover. A focused owner
fix needs regression coverage and review. Suggested direction from Rocko: account
for unsettled pending runs when choosing followUp; do not blindly change logic
from this note alone. Test cleanup and event synchronization also need correction.

## Provenance and gates

Rocko reports frozen Discord files match row21 commit1ac812d3, not the stated
archive basec4fc8e7d in HANDOFF. Darkwing requested Filbert's construction evidence
and append-only provenance correction outside frozen R1. Do not rewrite the old
handoff or infer its base from a mutable HEAD.

The later 351/351 bounded run remains valid narrow evidence; the earlier failure
is not erased. Integration stays held for owner disposition and provenance
reconciliation. No live action, publication, operator acceptance or GateF claim.