Add 'users/glittershark/xanthous/' from commit '53b56744f4'

git-subtree-dir: users/glittershark/xanthous
git-subtree-mainline: 91f53f02d8
git-subtree-split: 53b56744f4

users/glittershark/xanthous/shell.nix

@@ -0,0 +1,30 @@
+{ nixpkgs ? import ./nixpkgs.nix {}, compiler ? "ghc865", withHoogle ? true }:
+let
+  inherit (nixpkgs) pkgs;
+
+  pkg = import ./pkg.nix { inherit nixpkgs; };
+
+  packageSet = (
+    if compiler == "default"
+    then pkgs.haskellPackages
+    else pkgs.haskell.packages.${compiler}
+  ).override {
+    overrides = import ./haskell-overlay.nix { inherit nixpkgs; };
+  };
+
+  haskellPackages = (
+    if withHoogle
+    then packageSet.override {
+      overrides = (self: super: {
+        ghc = super.ghc // { withPackages = super.ghc.withHoogle; };
+        ghcWithPackages = self.ghc.withPackages;
+      } // (import ./haskell-overlay.nix { inherit nixpkgs; }) self super);
+    }
+    else packageSet
+  );
+
+  drv = haskellPackages.callPackage pkg {};
+
+  inherit (pkgs.haskell.lib) addBuildTools;
+in
+(addBuildTools drv (with haskellPackages; [ cabal-install ])).env