Show error when an invalid feature is added

[saiintbrisson]

Is your feature request related to a problem? Please describe. Sometimes a typo is committed when declaring a feature, and I don't get feedback until I try compiling the project.

Describe the solution you'd like It would be helpful to add an error on the feature declaration line, or perhaps below the feature itself.

[saiintbrisson]

After giving it a look, I figured that it might not be possible, and therefore I will close this issue

[WilliamVenner]

@SaiintBrisson This is actually possible, you can reopen this

[WilliamVenner]

Well, it's possible, but after a review of the parsing code it would take a lot of work and a huge refactor. Might not be worth it.

[saiintbrisson]

Yeah, that's what I thought too, I'll leave this open for now, the maintainers may close this if they want to.

[serayuzgur]

@saiintbrisson if you describe how to check it, I can take a look at the parser and see how much time it will take.

[lvkv]

This would be a great enhancement. I think it'd also work well with crate feature listing and/or feature autocomplete. Does this already exist in the Crates extension?