chainerror/booksrc/tutorial11.md

# Debug for the ErrorKind

One small improvement at the end of the tutorial is to fix the debug output of
`Func1ErrorKind`. As you probably noticed, the output doesn't say much of the enum.

~~~
Debug Error:
src/main.rs:35: Func2
[…]
~~~

As a lazy shortcut, we implement `Debug` by calling `Display` and end up with

~~~
Debug Error:
src/main.rs:40: func1 error calling func2
[…}
~~~

which gives us a lot more detail.

To create your own Errors, you might find [crates](https://crates.io) which create enum `Display+Debug` via derive macros.

Also noteworthy is [custom_error](https://crates.io/crates/custom_error) to define your custom errors,
which can then be used with `chainerror`.

~~~rust
{{#include ../examples/tutorial11.rs}}
# #[allow(dead_code)]
# mod chainerror {
{{#rustdoc_include ../src/lib.rs:-1}}
# }
~~~