title: Webpack Uglify plugin returns "Killed" on Ubuntu
body: <p>On my remote server (Ubuntu 14.04 x64), whenever I try to uglify my bundles, the process simply returns "Killed". When I don't uglify, it's just fine. </p>
  
  <p>Has anyone run into this? When I do it on my local Mac, it's fine (although I just tested it and it took 1.4 mins).</p>
  
  <p>This is my webpack.config: </p>
  
  <pre><code>var webpack = require('webpack');
  
  function makeConfig(opts) {
      var config = {
  
          entry: {
              app: ['./public/scripts/main.js'],
              vendor: ['lodash', 'react', 'react/lib/ReactCSSTransitionGroup', 'react-router', 'reqwest', 'd3']
          },
  
          stats: {
              colors: true,
              reasons: true
          },
  
          output: {
              devtool: (opts.env === 'dev' ? '#eval-source-map' : ''),
              path: 'dist/scripts',
              filename: '[name].bundle.js'
          },
  
          plugins: [
              new webpack.DefinePlugin({
                  ENV: opts.env
              }),
              new webpack.optimize.CommonsChunkPlugin('vendor.bundle.js')
          ],
  
          module: {
              loaders: [
                  { test: /\.jsx?$/, loader: 'jsx-loader' }
              ]
          }
      };
  
      if(opts.env === 'prod') {
          config.plugins.push(
              new webpack.optimize.UglifyJsPlugin(),
              new webpack.optimize.DedupePlugin()
          );
      }
  
      return config;
  }
  
  module.exports = makeConfig;
  </code></pre>
  
  <p>and it's called by gulp like so: </p>
  
  <pre><code>gulp.task('webpack', ['cleanScripts'], function(done) {
      webpack(webpackConfig, function(err, stats) {
          if(err) {
              console.error(err);
              throw new gutil.PluginError('webpack', err);    
          }
          else {
              done();
          }
      });
  });
  </code></pre>