Error while building

Hello :) I tried to build from the master branch:

$ npm run build 

> lovli.js@0.7.2 build /home/user/Code/horizon/lovli.js
> webpack --config=config/webpack/webpack.config.client.prod.js && webpack --config=config/webpack/webpack.config.server.js

Built client in 3.881s.
Hash: 3bc8a0846f62d813fe74
Version: webpack 1.13.0
Time: 3882ms
   [0] multi app 28 bytes {0} [built]
    + 472 hidden modules

ERROR in /home/user/Code/horizon/lovli.js/~/css-loader!/home/user/Code/horizon/lovli.js/static/vendor/font-awesome/css/font-awesome.min.css
Module build failed: TypeError: Cannot read property 'value' of undefined
    at reduce (/home/user/Code/horizon/lovli.js/node_modules/cssnano/dist/lib/reduceTimingFunctions.js:44:26)
    at walk (/home/user/Code/horizon/lovli.js/node_modules/postcss-value-parser/lib/walk.js:7:22)
    at ValueParser.walk (/home/user/Code/horizon/lovli.js/node_modules/postcss-value-parser/lib/index.js:18:5)
    at /home/user/Code/horizon/lovli.js/node_modules/cssnano/dist/lib/reduceTimingFunctions.js:65:72
    at /home/user/Code/horizon/lovli.js/node_modules/postcss/lib/container.js:100:28
    at /home/user/Code/horizon/lovli.js/node_modules/postcss/lib/container.js:81:26
    at Rule.each (/home/user/Code/horizon/lovli.js/node_modules/postcss/lib/container.js:68:22)
    at Rule.walk (/home/user/Code/horizon/lovli.js/node_modules/postcss/lib/container.js:80:21)
    at /home/user/Code/horizon/lovli.js/node_modules/postcss/lib/container.js:83:32
    at Root.each (/home/user/Code/horizon/lovli.js/node_modules/postcss/lib/container.js:68:22)
    at Root.walk (/home/user/Code/horizon/lovli.js/node_modules/postcss/lib/container.js:80:21)
    at Root.walkDecls (/home/user/Code/horizon/lovli.js/node_modules/postcss/lib/container.js:98:25)
    at /home/user/Code/horizon/lovli.js/node_modules/cssnano/dist/lib/reduceTimingFunctions.js:64:13
    at LazyResult.run (/home/user/Code/horizon/lovli.js/node_modules/postcss/lib/lazy-result.js:206:20)
    at /home/user/Code/horizon/lovli.js/node_modules/postcss/lib/lazy-result.js:120:37
    at LazyResult.asyncTick (/home/user/Code/horizon/lovli.js/node_modules/postcss/lib/lazy-result.js:134:15)
    at /home/user/Code/horizon/lovli.js/node_modules/postcss/lib/lazy-result.js:132:27
    at LazyResult.asyncTick (/home/user/Code/horizon/lovli.js/node_modules/postcss/lib/lazy-result.js:134:15)
    at /home/user/Code/horizon/lovli.js/node_modules/postcss/lib/lazy-result.js:132:27
    at LazyResult.asyncTick (/home/user/Code/horizon/lovli.js/node_modules/postcss/lib/lazy-result.js:134:15)
    at /home/user/Code/horizon/lovli.js/node_modules/postcss/lib/lazy-result.js:132:27
    at LazyResult.asyncTick (/home/user/Code/horizon/lovli.js/node_modules/postcss/lib/lazy-result.js:134:15)
    at /home/user/Code/horizon/lovli.js/node_modules/postcss/lib/lazy-result.js:125:31
 @ /home/user/Code/horizon/lovli.js/static/vendor/font-awesome/css/font-awesome.min.css 4:14-96
Built server in 1.144s.
Hash: af13ec09bf81c490fa24
Version: webpack 1.13.0
Time: 1148ms
           Asset    Size  Chunks             Chunk Names
server.bundle.js  450 kB       0  [emitted]  main
  [18] ../db.js 109 bytes {0} [built]
  [19] ../page.js 103 bytes {0} [built]
  [20] ./devProps.js 141 bytes {0} [built]
    + 66 hidden modules

Also:

$ node --version
v6.2.0