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

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

users/glittershark/xanthous/default.nix

@@ -0,0 +1,19 @@
+{ nixpkgs ? import ./nixpkgs.nix {}
+, compiler ? "ghc865"
+, failOnWarnings ? false
+}:
+let
+  inherit (nixpkgs) pkgs lib;
+  inherit (lib) id;
+  inherit (pkgs) fetchurl;
+  all-hies = import (fetchTarball {
+    url = "https://github.com/infinisil/all-hies/archive/4b6aab017cdf96a90641dc287437685675d598da.tar.gz";
+    sha256 = "0ap12mbzk97zmxk42fk8vqacyvpxk29r2wrnjqpx4m2w9g7gfdya";
+  }) {};
+  hie = all-hies.selection { selector = p: { inherit (p) ghc865; }; };
+  xanthous =
+    (if failOnWarnings then pkgs.haskell.lib.failOnAllWarnings else id)
+      ((pkgs.haskellPackages
+      .extend (import ./haskell-overlay.nix { inherit nixpkgs; })
+    ).callPackage (import ./pkg.nix { inherit nixpkgs; }) {}); in
+xanthous // { inherit hie; }