rls: tie version to rustc's

pkgs/development/tools/rust/rls/default.nix

@@ -1,47 +0,0 @@
-{ stdenv, fetchFromGitHub, rustPlatform
-, openssh, openssl, pkgconfig, cmake, zlib, curl, libiconv
-, CoreFoundation, Security }:
-
-rustPlatform.buildRustPackage rec {
-  pname = "rls";
-  # with rust 1.x you can only build rls version 1.x.y
-  version = "1.36.0";
-
-  src = fetchFromGitHub {
-    owner = "rust-lang";
-    repo = pname;
-    rev = version;
-    sha256 = "1mclv0admxv48pndyqghxc4nf1amhbd700cgrzjshf9jrnffxmrn";
-  };
-
-  cargoSha256 = "1yli9540510xmzqnzfi3p6rh23bjqsviflqw95a0fawf2rnj8sin";
-
-  # a nightly compiler is required unless we use this cheat code.
-  RUSTC_BOOTSTRAP=1;
-
-  # rls-rustc links to rustc_private crates
-  CARGO_BUILD_RUSTFLAGS = if stdenv.isDarwin then "-C rpath" else null;
-
-  nativeBuildInputs = [ pkgconfig cmake ];
-  buildInputs = [ openssh openssl curl zlib libiconv ]
-    ++ (stdenv.lib.optionals stdenv.isDarwin [ CoreFoundation Security ]);
-
-  doCheck = true;
-  preCheck = ''
-    # client tests are flaky
-    rm tests/client.rs
-  '';
-
-  doInstallCheck = true;
-  installCheckPhase = ''
-    $out/bin/rls --version
-  '';
-
-  meta = with stdenv.lib; {
-    description = "Rust Language Server - provides information about Rust programs to IDEs and other tools";
-    homepage = https://github.com/rust-lang/rls/;
-    license = with licenses; [ asl20 /* or */ mit ];
-    maintainers = with maintainers; [ symphorien ];
-    platforms = platforms.all;
-  };
-}