Anyhow

This is a Rust library (crate) that provides a flexible, concrete error type built atop the standard std::error::Error trait. Its primary goal is to make error handling in applications easy: instead of defining lots of custom error types, you can use anyhow::Error (or the alias anyhow::Result<T>) for fallible functions. The crate supports attaching context to errors, so you can convert a low-level error (like “file not found”) into one with richer diagnostics (“Failed to read instructions from path X”) using .context() or .with_context(). It supports downcasting (so you can inspect the underlying error type), and for recent versions of Rust, it will capture backtraces by default when the underlying error type doesn’t already. It also supports no_std mode (in limited form) by disabling default features. The README distinguishes it from library-oriented error crates (like thiserror): use anyhow when you just care about application-level error handling, not fine-grained types.