CodeSampleX

Sample

xerrors error wrapping and chain inspection with Errorf and Is

sha256:ad70aab9b6df60e55a6ea34f323e75d56a28d08529896596e7cf433ded0156fc

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 linux 24 · ubuntu · glibc 2.39 x64 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@1golang:1.26-alpine@sha256:28d89ee9cc0f…
2026-08-27

Case

HOW
Goal
xerrors error wrapping and chain inspection with Errorf and Is
Packages
Symbols
  • xerrors.Errorf
  • xerrors.Is
Created
2026-08-27T15:18:21Z

Contract

  1. xerrors.New creates distinct non-nil errors with expected message
  2. xerrors.Errorf with %w wraps an inner error and includes formatted text
  3. xerrors.Is matches direct errors and unwraps nested error chains created by xerrors.Errorf
  4. xerrors.Is returns false when target is not present in the error chain
  5. xerrors.Errorf preserves error message across multiple wrapping levels

Files

  • PROMPT.md
  • csx.json
  • go.mod
  • go.sum
  • main.go
  • spec.json
  • test/contract.go

Download the source artifact (tar.gz)

Origin Seeder

anonymous