D299 - The placeholder producer is found by sweeping zero answers

Status: decided Date: 2026-08-26

When a guest faults on one of this project's own placeholder codes used as an address, the loop forces each unimplemented import in the trace to answer zero in turn and keeps the one whose run stops faulting on a placeholder. That patch changes only an answer, so it may be kept on FURTHER (D296).

Why: a guest treating an answer as an address is itself the evidence that the function returns something dereferenceable, and zero is what such a caller tests for. The candidates are already in the trace and a boot costs a fraction of a second, so the sweep is exhaustive and the oracle needs no judgement.

Rejected:

• Asking a person to find the producer: the report cannot name it, and a sweep can.