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.