Function probe 

pub fn probe(schema: &Value) -> ProbeOutcome

Runs typify against schema (a full combined-schema JSON document, the same shape build.rs feeds it) inside catch_unwind, classifying the result. Temporarily installs a panic hook to capture the panic location (the payload alone doesn’t carry it), always restoring the previous hook before returning - there is no early return between install and restore, so this stays paired even on the panicking path. Serialized process-wide via probe_lock - see its docs.