Sample
tokio 1.43.0: Spawning non-Send futures in Tokio requires driving a LocalSet explicitly, avoiding uncontextualized spawn_local panics and unpolled task starvation
Verified sample for cargo tokio 1.43.0: Spawning non-Send futures in Tokio requires driving a LocalSet explicitly, avoiding uncontextualized spawn_local…
sha256:9b9720fef342edf7ef51c61e4781caeafe87bc3863b3fdfe9efd67fdb0a2caf8
This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured.
How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people.
MIT-0
Execution evidence
The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.
- Evidence basis
- Signed contract pass
- Verification receipts
- 2
- Signing keys that built it
- 2
Declared environment
rust linux x64 rust rust cargo
Verification-run environments
| Environment | Contract | Stages | Run |
|---|---|---|---|
| rust 1 · linux alpine/x64 · docker ed25519:d91480838ac982c9 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · cargo@1 |
2026-08-15 |
| rust 1 · linux alpine/x64 · docker ed25519:2175b912ea1c23b1 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · cargo@1 |
2026-08-18 |
Case
HOW- Goal
- Spawning non-Send futures in Tokio requires driving a LocalSet explicitly, avoiding uncontextualized spawn_local panics and unpolled task starvation
- Packages
- Symbols
-
- tokio::task::LocalSet
- tokio::task::spawn_local
- tokio::task::LocalSet::run_until
- tokio::task::LocalSet::spawn_local
- Environment
- rust
- Created
- 2026-08-15T17:12:48Z
Contract
- assert tokio::task::spawn_local panics at runtime when called without an active LocalSet context on the current thread
- assert tokio::task::LocalSet enables spawning non-Send futures across async tasks using thread-local Rc and RefCell
- assert tokio::task::spawn_local tasks execute on the exact same OS thread as the LocalSet driver on both single-thread and multi-thread runtimes
- assert tokio::task::LocalSet queued tasks do not execute on immediate-ready run_until futures until the driving future yields
- assert tokio::task::LocalSet tasks yield and interleave cooperatively on a single thread without synchronization locks
Files
- Cargo.lock
- Cargo.toml
- NOTES.md
- csx.json
- src/lib.rs