anchor.diff: -{ stdenv, fetchFromGitHub, rustPlatform
  +{ stdenv, makeWrapper, fetchFromGitHub, rustPlatform
   , openssh, openssl, pkgconfig, cmake, zlib, curl, libiconv
   , CoreFoundation, Security }:
   
  
positive.code:   CARGO_BUILD_RUSTFLAGS = if stdenv.isDarwin then "-C rpath" else null;
  
    nativeBuildInputs = [ pkgconfig cmake ];
    buildInputs = [ openssh openssl curl zlib libiconv rustPlatform.rust.rustc.llvm ]
      ++ (stdenv.lib.optionals stdenv.isDarwin [ CoreFoundation Security ]);
  
    doCheck = true;
  
negative.code:     $out/bin/rls --version
    '';
  
    RUST_SRC_PATH = rustPlatform.rustcSrc;
    postInstall = ''
      wrapProgram $out/bin/rls --set-default RUST_SRC_PATH ${rustPlatform.rustcSrc}
    '';
  
    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/";
  