This is a fork of the [`annotate-snippets` crate]. The principle motivation for this fork, at the time of writing, is [issue #167]. Specifically, we wanted to upgrade our version of `annotate-snippets`, but do so _without_ changing our diagnostic message format. This copy of `annotate-snippets` is basically identical to upstream, but with an extra `Level::None` variant that permits skipping over a new non-optional header emitted by `annotate-snippets`. More generally, it seems plausible that we may want to tweak other aspects of the output format in the future, so it might make sense to stick with our own copy so that we can be masters of our own destiny. [issue #167]: https://github.com/rust-lang/annotate-snippets-rs/issues/167 [`annotate-snippets` crate]: https://github.com/rust-lang/annotate-snippets-rs