Not able to install loader in Webpacker - ruby-on-rails

Question

I'm trying to follow a getting started guide, of installing a npm package called Vux. It's basically a UI written in Vue.js. The guide says that i need to modify a Webpack config file to include vux loader. Everything looks pretty straight-forward, my config file should looke like that:
const vuxLoader = require('vux-loader')
const webpackConfig = originalConfig
module.exports = vuxLoader.merge(webpackConfig, {
plugins: ['vux-ui']
})
I have a plain Webpacker config file generated by Rails/Webpacker and, after following a doc, it looks like that:
# config/webpack/environment.js
const { environment } = require('#rails/webpacker')
const vuxLoader = require('vux-loader')
module.exports = vuxLoader.merge(environment, {
plugins: ['vux-ui']
})
You can see that file on git hub here
However, after that change, Webpack throws:
/Volumes/SUPPORT/Workspace/Personal/hcpl/node_modules/vux-loader/src/index.js:285
config.plugins.push(new webpack.LoaderOptionsPlugin({
^
TypeError: config.plugins.push is not a function
at Function.module.exports.merge (/Volumes/SUPPORT/Workspace/Personal/hcpl/node_modules/vux-loader/src/index.js:285:20)
at Object.<anonymous> (/Volumes/SUPPORT/Workspace/Personal/hcpl/config/webpack/environment.js:7:28)
at Module._compile (module.js:641:30)
at Object.Module._extensions..js (module.js:652:10)
at Module.load (module.js:560:32)
at tryModuleLoad (module.js:503:12)
at Function.Module._load (module.js:495:3)
at Module.require (module.js:585:17)
at require (internal/module.js:11:18)
at Object.<anonymous> (/Volumes/SUPPORT/Workspace/Personal/hcpl/config/webpack/development.js:1:83)
Does anyone have any idea what have i done wrong in here? I'm not too experienced with Webpack nor the Webpacker setup makes it even more complicated to find/test any solution from the internet.