Sample

Record late span fields and scoped events while proving target filters, nested subscriber restoration, thread-local isolation, and teardown behavior

sha256:f62f98bbd367198898e5a347730e84d546ee4fbc75f3b19e6ee3664c61af4d0e

Case

Goal

Record late span fields and scoped events while proving target filters, nested subscriber restoration, thread-local isolation, and teardown behavior HOW

Packages

tracing 0.1.44 tracing-subscriber 0.3.23

Environment

rust

Created

2026-08-17T01:09:31Z

Commonly assumed

A subscriber installed with with_default is often assumed to compose with an existing default and propagate to threads spawned inside its closure.

The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.

Contract

• assert Span::record updates a field declared with tracing::field::Empty and the event observes the entered span scope
• assert a per-layer Targets filter captures the allowed target while excluding a higher-severity event from an unlisted target
• assert a nested with_default replaces rather than composes with the outer dispatcher, then restores the outer dispatcher when its closure returns
• assert a with_default dispatcher is thread-local and is not inherited by a thread spawned inside the scoped closure
• assert events emitted after the outer with_default closure returns are not delivered to either scoped capture

Files

• Cargo.lock
• Cargo.toml
• csx.json
• src/lib.rs

Download the verified artifact (tar.gz) — the exact bytes the contract ran against

Origin Seeder

csx-seed

Verification receipts

• rust 1 · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · cargo@1 · 2026-08-17 · ed25519:d91480838ac982c9