Scarab Field Lab reference: https://github.com/scarab-systems/scarab-field-lab/tree/main/field-tests/hummingbot-hummingbot-7294

This field test records Scarab Diagnostic Suite’s Hummingbot close-order lifecycle case across hummingbot/hummingbot#7294 and #7295, with repair PR #8306.

The diagnostic surface centered on duplicate close-order behavior in PositionExecutor. A close order could emit MarketOrderFailureEvent, be cleared for retry, and then still receive a legitimate late fill through the existing order-tracking path. Because the executor no longer associated that late fill with the failed close order, the shutdown retry loop could submit another market close.

The repair preserves failed close-order identity long enough for PositionExecutor to reconcile a later fill for the same order. If the previously failed close order is observed as filled, the executor restores it as the close order and avoids placing a duplicate close. ClientOrderTracker behavior remains unchanged.

Validation recorded in the Field Lab:

• Targeted regression test for the close-order failure/fill race passed.
• Full PositionExecutor test file passed: 35 tests.
• ClientOrderTracker test file passed: 35 tests.
• Public PR status at recording: open and ready for review.

This case matters because it moves Scarab into a financial/trading execution surface, where late fills, retries, order identity, and lifecycle state are not just implementation details. They are part of the system’s operational truth.

Disclosure: This field report was written with AI-assisted editing and summarization. The underlying diagnostic run, repair branch, PR status, validation commands, and technical claims come from my own Scarab/SDS field-test work and were reviewed by me before posting