Sample
#[error(transparent)] forwards both Display and Error::source to the inner error rather than wrapping the inner error as the cause layer
sha256:115c8c422a1ed72be811ab6ecb1f995940e32fd286cfe04c38e865c43df7feb6
PUBLISHED
L3_CONTRACT_PASS
MIT-0
Execution evidence
Declared environment and signed verification runs are separated so you can see exactly what this sample proves.
Evidence basisSigned contract pass
Verification receipts1
Verification levelL3_CONTRACT_PASS
Declared environment
- Execution context
- rust
- Operating system
- linux
- Architecture
- x64
- Runtime
- rust
- Language
- rust
- Package manager
- cargo
Verification-run environments
- Execution context
- rust 1
- Operating system
- linux alpine · musl
- Architecture
- x64
- Runtime
- rust 1
- Language
- rust
- Package manager
- cargo
- Execution
- container · docker
CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · cargo@1 · 2026-08-17
Case
- Goal
- #[error(transparent)] forwards both Display and Error::source to the inner error rather than wrapping the inner error as the cause layer HOW
- Packages
-
thiserror 2.0.20
- Environment
- rust
- Created
- 2026-08-17T18:49:30Z
Commonly assumed
#[error(transparent)] causes Error::source to return the wrapped error as Some(&inner)
The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.
Contract
- Calling Error::source on an error deriving Error with #[error(transparent)] delegates directly to inner.source(), returning None when wrapping a root error and omitting the wrapped type from the error cause chain.
- Display formatting on a transparent wrapper outputs the exact string of the inner error without wrapper decoration.
- Standard #[error("...")] with #[source] establishes the wrapped error as the direct causal source returning Some(&inner).
- Error chain traversal over a transparent variant produces one fewer level than a standard causal wrapper because the transparent type does not insert itself as a source layer.
Files
- Cargo.lock
- Cargo.toml
- NOTES.md
- csx.json
- src/lib.rs
Download the source artifact (tar.gz)
Origin Seeder
csx-seed
Verification receipts
- rust 1 · linux alpine/x64 · docker · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · cargo@1 · 2026-08-17 · ed25519:d91480838ac982c9