hopglass: test if hopglass works on nixos

pkg-hopglass-fe.nix

@@ -0,0 +1,44 @@
+{ stdenv, lib, pkgs, python, nodejs-11_x, fetchFromGitHub, fetchzip, fetchurl, conf }:
+let
+  nodejs = nodejs-11_x;
+  yarn2nix = import (fetchFromGitHub {
+    rev = "3f2dbb08724bf8841609f932bfe1d61a78277232";
+    owner = "moretea";
+    repo = "yarn2nix";
+    sha256 = "142av7dwviapsnahgj8r6779gs2zr17achzhr8b97s0hsl08dcl2";
+  }) { inherit pkgs nodejs; };
+  origPackage = builtins.fromJSON (builtins.readFile ./package.json);
+  src = fetchFromGitHub {
+    rev = "fc09b591dc2b9dd867559ea008f1177d52a824dd";
+    owner = "hopglass";
+    repo = "hopglass";
+    sha256 = "0s9x466jqn7swbd35kjiaqk2lmcy9fnykhcnb1b10a2l35q655cl";
+  };
+in
+yarn2nix.mkYarnPackage {
+  name = "hopglass-frontend";
+  src = src;
+  installPhase = ''
+    echo ---------------------------------------------------------------------------- installPhase
+    set -x
+    #yarn --offline build
+    ls -l
+    cp -R $src/. .
+    node_modules/.bin/grunt --force
+    mkdir -p $out
+    set +x
+  '';
+  distPhase = ''
+    cp -Rv build/* $out/
+    ln -s "$conf" $out/config.json
+  '';
+  allowedReferences = [ "out" ];
+  yarnPreBuild = ''
+    mkdir -p $HOME/.node-gyp/${nodejs.version}
+    echo 9 > $HOME/.node-gyp/${nodejs.version}/installVersion
+    ln -sfv ${nodejs}/include $HOME/.node-gyp/${nodejs.version}
+  '';
+  # work around some purity problems in nix
+  #yarnLock = ./yarn.lock;
+  #packageJSON = ./package.json;
+}