I tried that. I got:
C:\Users\digit>rustup component add rls
error: component ‘rls’ for target ‘x86_64-pc-windows-msvc’ is unavailable for download for channel ‘nightly’
If you require these components, please install and use the latest successful build version,
which you can find at https://rust-lang-nursery.github.io/rust-toolstate.
After determining the correct date, install it with a command such as:
rustup toolchain install nightly-2018-12-27
Then you can use the toolchain with commands such as:
cargo +nightly-2018-12-27 build
I can’t work out how to get “the correct date”.