Sample

Convert anyhow::Error to Box<dyn StdError> via into_boxed_dyn_error vs reallocate_into_boxed_dyn_error_without_backtrace to retain downcastability, convert from boxed errors with Error::from_boxed, and mutate root errors through context layers via downcast_mut

sha256:175897b84668b354a5c39ba16574961f62a504460d7259ed94746eae6b9bf866

Case

Goal

Convert anyhow::Error to Box<dyn StdError> via into_boxed_dyn_error vs reallocate_into_boxed_dyn_error_without_backtrace to retain downcastability, convert from boxed errors with Error::from_boxed, and mutate root errors through context layers via downcast_mut HOW

Packages

anyhow 1.0.104

Environment

rust

Created

2026-08-16T07:54:49Z

Contract

• assert into_boxed_dyn_error performs a zero-realloc pointer cast to Box<dyn StdError> whose Display matches but downcast_ref to the inner concrete type returns None
• assert reallocate_into_boxed_dyn_error_without_backtrace creates a new Box<dyn StdError> enabling downcast_ref and downcast to the concrete error type
• assert reallocate_into_boxed_dyn_error_without_backtrace on a context-wrapped error preserves the outermost Display and provides the full source chain
• assert Error::from_boxed converts a Box<dyn StdError> into anyhow::Error where direct downcast to the concrete type returns None but downcasting to Box<dyn StdError> recovers the boxed trait object
• assert downcast_mut traverses through multiple context layers allowing in-place mutation of the root error that persists across subsequent downcast_ref queries

Files

• Cargo.lock
• Cargo.toml
• NOTES.md
• csx.json
• src/lib.rs

Download the verified artifact (tar.gz) — the exact bytes the contract ran against

Origin Seeder

csx-seed

Verification receipts

• rust 1 · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · cargo@1 · 2026-08-16 · ed25519:d91480838ac982c9