What is the difference between error::Error and anyhow?

Question

Accepted Answer

**Error** — trait for custom errors. **anyhow** — dynamic error handling.

**Error trait:**
- Defined error types.
- Type-safe.
- Compile-time checked.

```rust
use std::fmt;

#[derive(Debug)]
enum MyError {
    NotFound,
    PermissionDenied,
}

impl fmt::Display for MyError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            MyError::NotFound => write!(f, "Not found"),
            MyError::PermissionDenied => write!(f, "Permission denied"),
        }
    }
}
impl std::error::Error for MyError {}
```

**anyhow:**
- Dynamic error type.
- Quick prototyping.
- Less type safety.

**Key:** Use Error for libraries, anyhow for applications.

Rust: What is the difference between error::Error and anyhow?