From f7bc0a3996a7b4d5fab08c404edaba0eeff31043 Mon Sep 17 00:00:00 2001
From: Luka Blaskovic <lblasc@tvbeat.com>
Date: Sun, 7 Jun 2020 14:12:28 +0000
Subject: [PATCH] rls: set RUST_SRC_PATH

rls has racer baked in which needs to know where the rust source
is to be able to do completion for std libs. By default rls will use:
$(rustc --print sysroot)/lib/rustlib/src/rust/src
which is nonexistent, this commit sets the correct source path
in a same way like it's done in racer expression.
---
 pkgs/development/compilers/rust/rls/default.nix | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/pkgs/development/compilers/rust/rls/default.nix b/pkgs/development/compilers/rust/rls/default.nix
index 4cf507fbf5c..05a9d5049a4 100644
--- a/pkgs/development/compilers/rust/rls/default.nix
+++ b/pkgs/development/compilers/rust/rls/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchFromGitHub, rustPlatform
+{ stdenv, makeWrapper, fetchFromGitHub, rustPlatform
 , openssh, openssl, pkgconfig, cmake, zlib, curl, libiconv
 , CoreFoundation, Security }:
 
@@ -23,7 +23,7 @@ rustPlatform.buildRustPackage {
   CARGO_BUILD_RUSTFLAGS = if stdenv.isDarwin then "-C rpath" else null;
 
   nativeBuildInputs = [ pkgconfig cmake ];
-  buildInputs = [ openssh openssl curl zlib libiconv rustPlatform.rust.rustc.llvm ]
+  buildInputs = [ openssh openssl curl zlib libiconv makeWrapper rustPlatform.rust.rustc.llvm ]
     ++ (stdenv.lib.optionals stdenv.isDarwin [ CoreFoundation Security ]);
 
   doCheck = true;
@@ -35,6 +35,11 @@ rustPlatform.buildRustPackage {
     $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/";