Luca

unresolved extern crate on rustc_* crates

3

### Check for existing issues - [X] Completed ### Describe the bug / provide steps to reproduce it added this to the cargo.toml and tried to use same setup for...

instead of using the [simple diff algorithm](https://github.com/Manishearth/compiletest-rs/blob/master/src/uidiff.rs) in the code, allow users to switch to some external tool like diff or [delta](https://github.com/dandavison/delta)

add cargo bless functionalty

16

I have been using `dylint` quite a lot, the `cargo bless` functionality would save so much repetitive work copying and pasting.