Sample
golang.org/x/sync 0.22.0: Handle errgroup derived context cancellation on successful Wait, first-completion error selection, cooperative sibling cancellation, and TryGo dropping semantics
Verified sample for golang golang.org/x/sync 0.22.0: Handle errgroup derived context cancellation on successful Wait, first-completion error selection…
sha256:470295d48f5f7621a26432793d4dd80d928dcb80ee6db8a57a43a16edbc4a5c6
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
go linux x64 go go gomod
Verification-run environments
| Environment | Contract | Stages | Run |
|---|---|---|---|
| go 1.26 · linux alpine/x64 · docker ed25519:d91480838ac982c9 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · golang@1 |
2026-08-15 |
| go 1.26 · linux alpine/x64 · docker ed25519:2175b912ea1c23b1 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · golang@1 |
2026-08-18 |
Case
HOW- Goal
- Handle errgroup derived context cancellation on successful Wait, first-completion error selection, cooperative sibling cancellation, and TryGo dropping semantics
- Packages
- Symbols
-
- errgroup.WithContext
- Group.Go
- Group.Wait
- Group.SetLimit
- Group.TryGo
- Environment
- go
- Created
- 2026-08-15T17:11:03Z
Contract
- assert errgroup.WithContext cancels its derived context on Wait() return even when all tasks return nil
- assert Wait returns the error of the first completed task and discards later errors without joining
- assert sibling cancellation requires explicit select on ctx.Done and sibling ctx.Err does not mask the root cause
- assert SetLimit with TryGo drops work immediately when saturated and SetLimit panics if modified while tasks run
Files
- NOTES.md
- contract_test.go
- csx.json
- go.mod
- go.sum