CodeSampleX

Sample

verify pkg:golang/golang.org/x/sync@v0.20.0

sha256:0fa644ee1e0f318a0b905b8b3970908eab540ba359f0ef126662640baa666f8f

Publication state. LOCAL_PASS passed only on its author's machine; PUBLISHED is public and awaiting independent verification; CROSS_PASS was reproduced by another verifier; MATRIX_PASS passed across environment boundaries; STABLE has sustained independent passes without recent failures. Evidence strength. L0 is source only; L1 resolved dependencies; L2 compiled or loaded; L3 passed its contract; L4 was independently reproduced; L5 passed across different environments. MIT-0

Execution evidence

Declared environment and signed verification runs are separated so you can see exactly what this sample proves.

Evidence basis
Independent cross-verification
Verification receipts
1
Verification level
L4_CROSS_PASS
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