Rails/Webpacker is not working - ruby-on-rails

Question

I have a Rails/React project. It's using Rails/webpack 3.3.0.
To precompile react code, I executed:
rails assets:precompile RAILS_ENV=development
But I am getting this error:
[Webpacker] Compilation failed:
(node:47256) DeprecationWarning: Tapable.apply is deprecated.
Call apply on the plugin directly instead (node:47256)
DeprecationWarning:
Tapable.plugin is deprecated. Use new API on .hooks instead
TypeError: dep.getResourceIdentifier is not a function
Is this something you faced before? Would you like to help me to fix thsi problem?
Here is my package.json
{
"dependencies": {
"#rails/webpacker": "3.3.0",
"babel-core": "6",
"babel-loader": "^7.1.4",
"babel-preset-react": "^6.24.1",
"caniuse-lite": "^1.0.3000697",
"classnames": "^2.2.5",
"coffee-loader": "^0.9.0",
"coffeescript": "^2.2.2",
"debounce": "^1.1.0",
"es6-shim": "^0.35.3",
"extract-text-webpack-plugin": "^4.0.0-beta.0",
"mobile-detect": "^1.4.1",
"prop-types": "^15.6.1",
"react": "16.0.0",
"react-addons-css-transition-group": "^16.0.0-alpha.3",
"react-addons-update": "^15.6.2",
"react-bootstrap": "^0.32.1",
"react-dom": "^16.2.0",
"react-dom-factories": "^1.0.2",
"react_ujs": "^2.4.4",
"uglifyjs-webpack-plugin": "^1.2.5",
"webpack": "4.0.0"
},
"devDependencies": {
"webpack-cli": "^2.0.15",
"webpack-dev-server": "^3.1.0"
},
"license": "UNLICENSED",
"private": true
}

Answer 1

The version of Webpacker you are using isn't compatible with Webpack 4.
However, it looks like support is close, Webpack 4.x support has been merged:
https://github.com/rails/webpacker/pull/1316
And there's a Webpacker 4.x preview release:
https://rubygems.org/gems/webpacker
So I believe you want to use Webpack 3.x for the time being, or go bleeding edge and try the prerelease.
With that said, I'm going to give the prerelease a go, I've been waiting for Webpack 4.x support!