Source HLS on Apple Silicon too, at long last

README.md

@@ -120,4 +120,4 @@ The description is optional and ignored by intlc. It can be used documentatively
 
 Check out `ARCHITECTURE.md`.
 
-Currently building against GHC 9.2.4. A Nix flake is included with all necessary dependencies. Contributors on Apple silicon will need to source GHC and HLS externally, for example via ghcup.
+Currently building against GHC 9.4.6. A Nix flake is included with all necessary dependencies.

flake.nix

@@ -1,36 +1,3 @@
-# There are two major considerations when picking a version of GHC for this
-# project.
-#
-# Firstly, we'd like the version we choose to have tooling available in Nix's
-# binary cache, without contributors having to mess around with additional
-# caches. This limits us to the "default" version of GHC in nixpkgs.
-#
-# With this in mind, we could simply use the `ghc` and `haskellPackages`
-# package and package set, however the following has been written with
-# flexibility in mind. Note that using `haskellPackages` implicitly brings the
-# default version of GHC into scope as it's merely an alias for the default
-# package set [1].
-#
-# Secondly, HLS is currently marked as broken on aarch64-darwin [2], which
-# impacts Apple silicon contributors. With this in mind we're also keen to
-# ensure that our chosen version of GHC is supported by HLS as distributed via
-# ghcup.
-#
-# This means we're effectively stuck with whichever version of GHC is both the
-# default for nixpkgs at some point in time - in the past is okay, as nixpkgs
-# is pinned and the cache is long-lived - and which has the requisite support
-# in ghcup as well. At time of writing that version is 9.4.6.
-#
-# Further complicating matters, GHC and HLS need to be sourced from the same
-# place to ensure that HLS was compiled against that same version of GHC, lest
-# we see "ABIs don't match" errors. Therefore aarch64-darwin contributors must
-# not only source HLS externally but also GHC.
-#
-# In short, don't upgrade GHC until it's the default in nixpkgs, and available
-# in ghcup and supported by HLS there as well.
-#
-# [1]: https://github.com/NixOS/nixpkgs/blob/master/doc/languages-frameworks/haskell.section.md#available-packages-haskell-available-packages
-# [2]: https://github.com/NixOS/nixpkgs/blob/a410420844fe1ad6415cf9586308fe7538cc7584/pkgs/development/compilers/llvm/7/compiler-rt/default.nix#L108
 {
   inputs = {
     nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
@@ -41,27 +8,26 @@
     flake-utils.lib.eachDefaultSystem (system:
       let pkgs = nixpkgs.legacyPackages.${system};
 
+          # We'll stick with the "default" version of GHC in nixpkgs to benefit
+          # from the binary cache:
+          #   https://github.com/NixOS/nixpkgs/blob/master/doc/languages-frameworks/haskell.section.md#available-packages-haskell-available-packages
           ghcVer = "ghc946";
-          haskPkgs = pkgs.haskell.packages."${ghcVer}";
 
-          hask = if system == flake-utils.lib.system.aarch64-darwin
-            then [ ]
-            else [
-              pkgs.haskell.compiler."${ghcVer}"
-              haskPkgs.haskell-language-server
-            ];
+          haskPkgs = pkgs.haskell.packages."${ghcVer}";
       in {
         devShells.default = pkgs.mkShell {
           nativeBuildInputs = with pkgs; [
             cabal-install
+            haskell.compiler."${ghcVer}"
+            haskPkgs.haskell-language-server
             hlint
             haskPkgs.hspec-golden
             stylish-haskell
 
             # For typechecking golden output
             nodejs
             yarn
-          ] ++ hask;
+          ];
         };
       });
 }