### Anyhow Option Context Example

Source: https://github.com/eyre-rs/eyre/blob/master/README.md

This example demonstrates how `anyhow` handles context for `Option` types using the `context` method.

```rust
use anyhow::Context;

let opt: Option<()> = None;
let result_static = opt.context("static error message");
let result_dynamic = opt.with_context(|| format!("{}" error message", "dynamic"));
```

--------------------------------

### Install and Use simple-eyre Handler

Source: https://github.com/eyre-rs/eyre/blob/master/simple-eyre/README.md

Install the simple-eyre handler before creating eyre::Report types. This example demonstrates creating a basic error and wrapping it.

```rust
use simple_eyre::eyre::{eyre, ResultExt, Report};

fn main() -> Result<(), Report> {
    simple_eyre::install()?;

    let e: Report = eyre!("oh no this program is just bad!");

    Err(e).wrap_err("usage example successfully experienced a failure")
}
```

--------------------------------

### Full Usage Example

Source: https://github.com/eyre-rs/eyre/blob/master/color-spantrace/README.md

Demonstrates setting up tracing, capturing spans across multiple functions, and colorizing the final SpanTrace.

```rust
use tracing::instrument;
use tracing_error::{ErrorLayer, SpanTrace};
use tracing_subscriber::{prelude::*, registry::Registry};

#[instrument]
fn main() {
    Registry::default().with(ErrorLayer::default()).init();

    let span_trace = one(42);
    println!("{}", color_spantrace::colorize(&span_trace));
}

#[instrument]
fn one(i: u32) -> SpanTrace {
    two()
}

#[instrument]
fn two() -> SpanTrace {
    SpanTrace::capture()
}
```

--------------------------------

### Setup Tracing Subscriber with ErrorLayer

Source: https://github.com/eyre-rs/eyre/blob/master/color-spantrace/README.md

Initialize a tracing subscriber with the ErrorLayer to enable error reporting.

```rust
use tracing_error::ErrorLayer;
use tracing_subscriber::{prelude::*, registry::Registry};

Registry::default().with(ErrorLayer::default()).init();
```

--------------------------------

### Install color-eyre Panic and Error Handlers

Source: https://github.com/eyre-rs/eyre/blob/master/color-eyre/README.md

Installs the necessary handlers for color-eyre to format panics and errors. This should be called early in your application's entry point.

```rust
use color_eyre::eyre::Result;

fn main() -> Result<()> {
    color_eyre::install()?;

    // ...
    # Ok(())
}
```

--------------------------------

### Eyre Option Handling Example

Source: https://github.com/eyre-rs/eyre/blob/master/README.md

This example shows how Eyre handles `Option` types using `ok_or_eyre` for static errors and `ok_or_else` for dynamic errors, aligning with Eyre's design principles.

```rust
use eyre::{eyre, OptionExt, Result};

let opt: Option<()> = None;
let result_static: Result<()> = opt.ok_or_eyre("static error message");
let result_dynamic: Result<()> = opt.ok_or_else(|| eyre!("{}" error message", "dynamic"));
```

--------------------------------

### Capture Span Trace with Theming

Source: https://github.com/eyre-rs/eyre/blob/master/color-spantrace/tests/data/theme_control.txt

Illustrates capturing a span trace within a test function that utilizes theming. This example requires the `tracing` crate and its `instrument` macro.

```rust
use tracing_subscriber::{prelude::*, registry::Registry};

#[instrument]
fn test_capture(x: u8) -> SpanTrace {
    #[allow(clippy::if_same_then_else)]
    if x == 42 {
        SpanTrace::capture()
    } else {
        SpanTrace::capture()
    }
}
```

--------------------------------

### Implement Custom Sections for Error Reports

Source: https://github.com/eyre-rs/eyre/blob/master/color-eyre/README.md

This example demonstrates how to add custom sections like stdout and stderr to error reports using the `SectionExt` trait. It's useful for capturing command output when errors occur.

```rust
use color_eyre::{eyre::eyre, SectionExt, Section, eyre::Report};
use std::process::Command;
use tracing::instrument;

trait Output {
    fn output2(&mut self) -> Result<String, Report>;
}

impl Output for Command {
    #[instrument]
    fn output2(&mut self) -> Result<String, Report> {
        let output = self.output()?;

        let stdout = String::from_utf8_lossy(&output.stdout);

        if !output.status.success() {
            let stderr = String::from_utf8_lossy(&output.stderr);
            Err(eyre!("cmd exited with non-zero status code"))
                .with_section(move || stdout.trim().to_string().header("Stdout:"))
                .with_section(move || stderr.trim().to_string().header("Stderr:"))
        } else {
            Ok(stdout.into())
        }
    }
}
```

--------------------------------

### Anyhow Option Context Usage

Source: https://github.com/eyre-rs/eyre/blob/master/eyre/README.md

Demonstrates how to use the `context` method on Option with Anyhow for static and dynamic error messages.

```rust
use anyhow::Context;

let opt: Option<()> = None;
let result_static = opt.context("static error message");
let result_dynamic = opt.with_context(|| format!("{} error message", "dynamic"));
```

--------------------------------

### Enable Anyhow Compatibility in Cargo.toml

Source: https://github.com/eyre-rs/eyre/blob/master/eyre/README.md

To enable the Anyhow compatibility layer, add the "anyhow" feature to your Eyre dependency in Cargo.toml.

```toml
eyre = { version = "0.6", features = ["anyhow"] }
```

--------------------------------

### Add color-spantrace to Cargo.toml

Source: https://github.com/eyre-rs/eyre/blob/master/color-spantrace/README.md

Add the color-spantrace crate and its dependencies to your project's Cargo.toml file.

```toml
[dependencies]
color-spantrace = "0.2"
tracing = "0.1"
tracing-error = "0.2"
tracing-subscriber = "0.3"
```

--------------------------------

### Eyre Option Context Usage

Source: https://github.com/eyre-rs/eyre/blob/master/eyre/README.md

Shows the equivalent usage with Eyre, utilizing `ok_or_eyre` for static errors and `ok_or_else` with `eyre!` for dynamic errors.

```rust
use eyre::{eyre, OptionExt, Result};

let opt: Option<()> = None;
let result_static: Result<()> = opt.ok_or_eyre("static error message");
let result_dynamic: Result<()> = opt.ok_or_else(|| eyre!("{} error message", "dynamic"));
```

--------------------------------

### Early Return with `bail!` Macro

Source: https://github.com/eyre-rs/eyre/blob/master/eyre/README.md

The `bail!` macro provides a shorthand for early returns with an `eyre::Report`, supporting format argument captures.

```rust
bail!("Missing attribute: {}", missing);
```

```rust
bail!("Missing attribute: {missing}");
```

--------------------------------

### Improve Debug Build Performance

Source: https://github.com/eyre-rs/eyre/blob/master/color-eyre/README.md

Optimize the performance of the 'backtrace' crate in debug builds by setting its optimization level to 3 in Cargo.toml. This mitigates performance degradation compared to the 'eyre' crate.

```toml
[profile.dev.package.backtrace]
opt-level = 3
```

--------------------------------

### Colorize SpanTrace

Source: https://github.com/eyre-rs/eyre/blob/master/color-spantrace/README.md

Capture a SpanTrace and print its colorized representation.

```rust
use tracing_error::SpanTrace;

let span_trace = SpanTrace::capture();
println!("{}", color_spantrace::colorize(&span_trace));
```

--------------------------------

### Create and Capture Spans

Source: https://github.com/eyre-rs/eyre/blob/master/color-spantrace/README.md

Define instrumented functions that capture SpanTrace objects.

```rust
use tracing::instrument;
use tracing_error::SpanTrace;

#[instrument]
fn foo() -> SpanTrace {
    SpanTrace::capture()
}
```

--------------------------------

### Panic Output with Theme Control

Source: https://github.com/eyre-rs/eyre/blob/master/color-eyre/tests/data/theme_panic_control_no_spantrace.txt

This output shows a typical panic message when color-eyre is configured with theme control. It displays the panic message, location, and a filtered backtrace. Run with COLORBT_SHOW_HIDDEN=1 to see hidden frames or RUST_BACKTRACE=full for source snippets.

```text
Compiling color-eyre v0.6.5 (/home/username/src/eyre/color-eyre)\n    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.42s\n     Running /home/username/src/eyre/target/debug/examples/theme_test_helper\nThe application panicked (crashed).\nMessage:  <non string panic payload>\nLocation: color-eyre/examples/theme_test_helper.rs:38:5\n\n  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ BACKTRACE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━\n                                ⋮ 7 frames hidden ⋮                               \n   8: std::panic::panic_any::he59a839a6a44e696\n      at /home/username/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panic.rs:260:5\n   9: theme_test_helper::main::hc5e7f338a9ea403d\n      at /home/username/src/eyre/color-eyre/examples/theme_test_helper.rs:38:5\n  10: core::ops::function::FnOnce::call_once::h70f9f848fb0cbb67\n      at /home/username/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/ops/function.rs:250:5\n                                ⋮ 16 frames hidden ⋮                              \n\nRun with COLORBT_SHOW_HIDDEN=1 environment variable to disable frame filtering.\nRun with RUST_BACKTRACE=full to include source snippets.\n
```

--------------------------------

### Creating One-Off Error Messages with `eyre!`

Source: https://github.com/eyre-rs/eyre/blob/master/eyre/README.md

Use the `eyre!` macro to construct `eyre::Report` instances with string interpolation for one-off error messages.

```rust
return Err(eyre!("Missing attribute: {}", missing));
```

```rust
return Err(eyre!("Missing attribute: {missing}"));
```

--------------------------------

### Wrapping Errors with Context

Source: https://github.com/eyre-rs/eyre/blob/master/eyre/README.md

Wrap lower-level errors with new messages using `wrap_err` or `wrap_err_with` to provide more context for debugging. This is useful for understanding the chain of failures.

```rust
use eyre::{ResultExt, Result};

fn main() -> Result<()> {
    ...
    it.detach().wrap_err("Failed to detach the important thing")?;

    let content = std::fs::read(path)
        .wrap_err_with(|| format!("Failed to read instrs from {}", path))?;
    ...
}
```

```console
Error: Failed to read instrs from ./path/to/instrs.json

Caused by:
    No such file or directory (os error 2)
```

--------------------------------

### Disable color-eyre Tracing Support

Source: https://github.com/eyre-rs/eyre/blob/master/color-eyre/README.md

Configure color-eyre to exclude tracing integration by modifying the Cargo.toml file. This reduces dependencies if tracing is not used.

```toml
[dependencies]
color-eyre = { version = "0.6", default-features = false }
```

--------------------------------

### Propagating Errors with `?` Operator

Source: https://github.com/eyre-rs/eyre/blob/master/eyre/README.md

Use `eyre::Result<T>` as a return type for fallible functions and the `?` operator to propagate errors that implement `std::error::Error`.

```rust
use eyre::Result;

fn get_cluster_info() -> Result<ClusterMap> {
    let config = std::fs::read_to_string("cluster.json")?;
    let map: ClusterMap = serde_json::from_str(&config)?;
    Ok(map)
}
```

--------------------------------

### Disable SpanTrace Capture by Default

Source: https://github.com/eyre-rs/eyre/blob/master/color-eyre/README.md

Prevent SpanTrace capture by default by setting the RUST_SPANTRACE environment variable to "0". This can reduce noise during debugging.

```rust
if std::env::var("RUST_SPANTRACE").is_err() {
    std::env::set_var("RUST_SPANTRACE", "0");
}
```

--------------------------------

### Custom Error Type with `thiserror`

Source: https://github.com/eyre-rs/eyre/blob/master/eyre/README.md

Define custom error types using `thiserror` for use with Eyre. This allows for structured error reporting and matching.

```rust
use thiserror::Error;

#[derive(Error, Debug)]
pub enum FormatError {
    #[error("Invalid header (expected {expected:?}, got {found:?})")]
    InvalidHeader {
        expected: String,
        found: String,
    },
    #[error("Missing attribute: {0}")]
    MissingAttribute(String),
}
```

--------------------------------

### Downcasting Errors

Source: https://github.com/eyre-rs/eyre/blob/master/eyre/README.md

Downcasting is supported for error types, allowing you to inspect the root cause of an error by value, shared reference, or mutable reference.

```rust
// If the error was caused by redaction, then return a
// tombstone instead of the content.
match root_cause.downcast_ref::<DataStoreError>() {
    Some(DataStoreError::Censored(_)) => Ok(Poll::Ready(REDACTED_CONTENT)),
    None => Err(error),
}
```

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