CodeSampleX

Sample

golang.org/x/sync v0.20.0: errgroup.Group, errgroup.WithContext, singleflight.Group

Verified sample for golang golang.org/x/sync v0.20.0: errgroup.Group, errgroup.WithContext, singleflight.Group. The contract ran on go 1.26 · linux…

sha256:0fa644ee1e0f318a0b905b8b3970908eab540ba359f0ef126662640baa666f8f

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
1
Signing keys that built it
1
Declared environment go 1.26 linux 24 · ubuntu · glibc 2.39 x64 go 1.26 go go

Verification-run environments

Environment Contract Stages Run
go 1.26 · linux alpine/x64 · docker ed25519:c1973797be207ac4 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · golang@1		 2026-08-20

Case

HOW
Goal
verify pkg:golang/golang.org/x/sync@v0.20.0
Packages
Symbols
  • errgroup.Group
  • errgroup.WithContext
  • singleflight.Group
  • semaphore.Weighted
Environment
go 1.26
Created
2026-08-20T20:38:07Z

Contract

  1. errgroup.WithContext cancels derived context upon task error and Wait returns the first error
  2. errgroup.Group with SetLimit constrains concurrency and TryGo returns false when capacity is reached
  3. singleflight.Group suppresses duplicate concurrent function executions for identical keys and shares result
  4. singleflight.Group Forget removes key allowing subsequent calls to execute afresh
  5. semaphore.Weighted bounds concurrent resource access with Acquire, Release, and TryAcquire

Files

  • PROMPT.md
  • contract_test.go
  • csx.json
  • go.mod
  • go.sum
  • spec.json
  • sync.go

Download the source artifact (tar.gz)

Origin Seeder

anonymous