rls: tie version to rustc's

pkgs/development/compilers/rust/default.nix

@@ -66,6 +66,7 @@
         inherit CoreFoundation Security;
       };
       clippy = self.callPackage ./clippy.nix { inherit Security; };
+      rls = self.callPackage ./rls { inherit CoreFoundation Security; };
     });
   };
 }

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

@@ -4,17 +4,17 @@
 
 rustPlatform.buildRustPackage rec {
   pname = "rls";
-  # with rust 1.x you can only build rls version 1.x.y
-  version = "1.36.0";
+  inherit (rustPlatform.rust.rustc) src version;
 
-  src = fetchFromGitHub {
-    owner = "rust-lang";
-    repo = pname;
-    rev = version;
-    sha256 = "1mclv0admxv48pndyqghxc4nf1amhbd700cgrzjshf9jrnffxmrn";
-  };
+  # changes hash of vendor directory otherwise
+  dontUpdateAutotoolsGnuConfigScripts = true;
 
-  cargoSha256 = "1yli9540510xmzqnzfi3p6rh23bjqsviflqw95a0fawf2rnj8sin";
+  cargoVendorDir = "vendor";
+  preBuild = ''
+    pushd src/tools/rls
+    # client tests are flaky
+    rm tests/client.rs
+  '';
 
   # a nightly compiler is required unless we use this cheat code.
   RUSTC_BOOTSTRAP=1;
@@ -27,10 +27,8 @@ rustPlatform.buildRustPackage rec {
     ++ (stdenv.lib.optionals stdenv.isDarwin [ CoreFoundation Security ]);
 
   doCheck = true;
-  preCheck = ''
-    # client tests are flaky
-    rm tests/client.rs
-  '';
+
+  preInstall = "popd";
 
   doInstallCheck = true;
   installCheckPhase = ''

pkgs/top-level/all-packages.nix

@@ -8288,9 +8288,7 @@ in
 
   pyo3-pack = callPackage ../development/tools/rust/pyo3-pack { };
   rainicorn = callPackage ../development/tools/rust/rainicorn { };
-  rls = callPackage ../development/tools/rust/rls {
-    inherit (darwin.apple_sdk.frameworks) CoreFoundation Security;
-  };
+  inherit (rustPackages) rls;
   rustfmt = rustPackages.rustfmt;
   rustracer = callPackage ../development/tools/rust/racer {
     inherit (darwin.apple_sdk.frameworks) Security;