vim + w0rp/ale, ale has LSP support and I now use it as a one stop shop for go to dec, find refs, and autocomplete. It has support for linting with cargo, rustc, rls, and autoformatting with rustfmt. rustup makes installing rls extremely painless.
the rust stuff in my vim dates to v. early post 1.0 and would love to link ale + rls up.
rustup component add rls-preview rust-analysis rust-src --toolchain nightly
let b:ale_linters = {'rust': ['rls','cargo','rustc']}
let g:ale_fixers = {'rust': ['rustfmt']}
let g:ale_completion_enabled = 1