A Rust library that makes panics a little less painful by nicely colorizing them and printing the relevant source snippets.

[dependencies]
color-backtrace = { version = "0.6" }

To enable it, simply place this code somewhere in your app initialization code:

color_backtrace::install();

If you want to customize some settings, you can instead do:

use color_backtrace::{default_output_stream, BacktracePrinter};
BacktracePrinter::new().message("Custom message!").install(default_output_stream());

• Colorize backtraces to be easier on the eyes
• Show source snippets if source files are found on disk
• Print frames of application code vs dependencies in different color
• Hide all the frames after the panic was already initiated
• Hide language runtime initialization frames

Unfortunately, defining custom init functions run before tests are started is currently not supported in Rust. Since initializing color-backtrace in each and every test is tedious even when wrapping it into a function, I recommended using the ctor crate for this.

Somewhere, preferably in your crate's main module, put the following code:

#[cfg(test)]
mod tests {
    use ctor::ctor;

    #[ctor]
    fn init_color_backtrace() {
        color_backtrace::install();
    }
}

You can also do this outside of a #[cfg(test)] section, in which case the panic handler is installed for both test and regular runs.