Support for include!() macro (e.g. cap'n'proto rust support)

[vlovich]

The way cap'n'proto works is it generates a file from a schema within build.rs. Within your lib.rs you'll do something like:

mod example_capnp {
  include!(concat!(env!("OUT_DIR"), "/capnp/example_capnp.rs"));
}

However rust-analyzer gives up and doesn't offer any completions for example_capnp::. I'm guessing it's because it doesn't know how to handle include! (& maybe env!?).

[bjorn3]

include!() and env!("OUT_DIR") are supported. If you are having issues, that is likely because the build script failed to run. I believe you can look at the Rust Analyzer Server output channel to see the result of running cargo by rust-analyzer for the purpose of running build scripts.