Debug code lens for Rust

[hdevalke]

I created a vscode extension to create a debug codelens for each test in a rust file. It does depend on CodeLLDB to start a debug session.

Do you think it make sense to add this functionality in the rls extension?

[nrc]

That sounds really cool! I think it might make sense to add it. I really want to focus on the debugging experience later in the year once we've released a 1.0. I don't think we should do this before 1.0, however: debugging support with Rust and lldb is not really mature (and we have tricky distribution issues to figure out there) and I'm not sure how we make depending on other extensions work.

[hdevalke]

Seems like #5 is also related to packaging a debug extensions. Extension dependencies make it possible to depend on other extensions. Once a specific debug dependency is chosen, a codelens could be added.

[Xanewok]

I think it makes sense to separate the debugging part and make users use that instead. However, I'm not really sure that hard-depending on CodeLLDB is good, since not everyone might want to pull in CodeLLDB, use it to install lldb (we'd still like to use rust-lldb instead, however this needs to be fixed upstream) and supposedly Windows support is flaky and C/C++ extension is preferred.
In short, we'd love to have this but I'm not entire sure in which configuration exactly we should do this.

[PhilParisot]

Would be really nice for the VScode extension to come with a debugger...

[PhilParisot]

We should probably close this issue and follow #5 instead.