Possibly a bug using options vs query.

[amir20]

Documentation suggests to use options to configure loaders but I had to use query.

ExtractTextPlugin.extract({
                fallbackLoader: 'style-loader',
                loader: [
                     {
                         loader: 'css-loader',
                         query: { importLoaders: 1}, // <--- should this be options? 
                     },
                     {
                         loader: 'postcss-loader',
                     }
                 ]
            })

This could be a bug. I couldn't figure out how to get css-loader configured with importLoaders otherwise.

[flying-sheep]

definitely true.

this still only supports webpack 1 style query, not options

[bebraw]

The plugin has been updated to use options. Instead of loader you should go with use now.