Add HLS back and avoid project.index-state

Author: hamishmack

cabal.project

@@ -12,9 +12,6 @@ repository cardano-haskell-packages
 
 -- See CONTRIBUTING for information about these, including some Nix commands
 -- you need to run if you change them
-
-index-state: 2022-09-27T18:00:00Z
-
 index-state:
   , hackage.haskell.org 2022-09-27T18:00:00Z
   , cardano-haskell-packages 2023-03-24T17:48:01Z

flake.lock

@@ -19,7 +19,7 @@
       flake = false;
     };
     haskellNix = {
-      url = "github:input-output-hk/haskell.nix/1dcbcc7790d20a6d51347fcda313dcabe27b984c";
+      url = "github:input-output-hk/haskell.nix";
       inputs.nixpkgs.follows = "nixpkgs";
       inputs.hackage.follows = "hackageNix";
     };

flake.nix

@@ -21,6 +21,11 @@ final: prev: with final; {
     index-state = "2022-09-27T00:00:00Z";
   };
 
+  haskell-language-server = haskell-nix.tool compiler-nix-name "haskell-language-server" {
+    version = "1.8.0.0";
+    index-state = "2023-03-13T00:00:00Z";
+  };
+
   haskellBuildUtils = prev.haskellBuildUtils.override {
     inherit compiler-nix-name;
     index-state = "2022-09-27T00:00:00Z";

nix/pkgs.nix

@@ -59,6 +59,10 @@ let
     packages = ps: builtins.attrValues (haskellLib.selectProjectPackages ps);
 
     tools = {
+      haskell-language-server = {
+        version = "1.8.0.0";
+        index-state = "2023-03-13T00:00:00Z";
+      };
     };
 
     # These programs will be available inside the nix-shell.