Nix improvements (#361)

Author: EncodePanda

.github/workflows/ci.yml

@@ -29,7 +29,7 @@ jobs:
       name: Cache ~/.stack
       with:
         path: ~/.stack
-        key: ${{ runner.os }}-${{ matrix.ghc }}-v4
+        key: ${{ runner.os }}-${{ matrix.ghc }}-v5
 
     - name: Add ~/.local/bin to PATH
       run: echo "$HOME/.local/bin" >> $GITHUB_PATH

default.nix

@@ -1,5 +1,5 @@
 { pkgs ? import ./haskell-pkgs.nix
-, haskellCompiler ? "ghc8101"
+, haskellCompiler ? "ghc8104"
 }:
 pkgs.haskell-nix.cabalProject {
   src = pkgs.haskell-nix.haskellLib.cleanGit {

haskell-pkgs.nix

@@ -1,18 +1,20 @@
 let
   # Fetch the latest haskell.nix and import its default.nix
-  haskellNix = import (builtins.fetchTarball{
-    url = "https://github.com/input-output-hk/haskell.nix/archive/f6663a8449f5e4a7393aa24601600c8f6e352c97.tar.gz";
-  }) {};
+  haskellNix = import
+    (builtins.fetchTarball {
+      url = "https://github.com/input-output-hk/haskell.nix/archive/1b9b05beed75a1be98405501fbb33ac1f080069e.tar.gz";
+    })
+    { };
 
-# haskell.nix provides access to the nixpkgs pins which are used by our CI,
-# hence you will be more likely to get cache hits when using these.
-# But you can also just use your own, e.g. '<nixpkgs>'.
-  nixpkgsSrc = haskellNix.sources.nixpkgs-2003;
+  # haskell.nix provides access to the nixpkgs pins which are used by our CI,
+  # hence you will be more likely to get cache hits when using these.
+  # But you can also just use your own, e.g. '<nixpkgs>'.
+  nixpkgsSrc = haskellNix.sources.nixpkgs-2009;
 
-# haskell.nix provides some arguments to be passed to nixpkgs, including some
-# patches and also the haskell.nix functionality itself as an overlay.
+  # haskell.nix provides some arguments to be passed to nixpkgs, including some
+  # patches and also the haskell.nix functionality itself as an overlay.
   nixpkgsArgs = haskellNix.nixpkgsArgs;
 
-# import nixpkgs with overlays
+  # import nixpkgs with overlays
 in
-  import nixpkgsSrc nixpkgsArgs
+import nixpkgsSrc nixpkgsArgs

shell.nix

@@ -1,27 +1,32 @@
-{ pkgs ? import ./haskell-pkgs.nix}:
-
+{ pkgs ? import ./haskell-pkgs.nix }:
 let
   hsPkgs = import ./. { inherit pkgs; };
 in
-  hsPkgs.shellFor {
-    # Include only the *local* packages of your project.
-    # packages = ps: with ps; [
-    # ];
+hsPkgs.shellFor {
+  # Include only the *local* packages of your project.
+  # packages = ps: with ps; [
+  # ];
 
-    # Builds a Hoogle documentation index of all dependencies,
-    # and provides a "hoogle" command to search the index.
-    # withHoogle = true;
+  # Builds a Hoogle documentation index of all dependencies,
+  # and provides a "hoogle" command to search the index.
+  # withHoogle = true;
 
-    # You might want some extra tools in the shell (optional).
-    # Some common tools can be added with the `tools` argument
-    tools = { cabal = "3.2.0.0"; hlint = "2.2.11"; };
-    # See overlays/tools.nix for more details
+  # You might want some extra tools in the shell (optional).
+  # Some common tools can be added with the `tools` argument
+  tools = {
+    cabal = "3.2.0.0";
+    hlint = "2.2.11";
+    stylish-haskell = "0.12.2.0";
+  };
+  # See overlays/tools.nix for more details
 
-    # Some you may need to get some other way.
-    buildInputs = with pkgs.haskellPackages;
-      [ ghcid ];
+  # Some you may need to get some other way.
+  buildInputs = [
+    pkgs.ghcid
+    pkgs.nixpkgs-fmt
+  ];
 
-    # Prevents cabal from choosing alternate plans, so that
-    # *all* dependencies are provided by Nix.
-    exactDeps = true;
-  }
+  # Prevents cabal from choosing alternate plans, so that
+  # *all* dependencies are provided by Nix.
+  exactDeps = true;
+}