Deploying Rails App via Heroku uses an old version of Node

Question

While trying to deploy my Rails app via Heroku "git push heroku master" on my Ubuntu 16.04 machine, I receive the following error:

[2/4] Fetching packages...
remote:          error @rails/[email protected]: The engine "node" is incompatible with this module. Expected version ">=8.16.0".
remote:        error An unexpected error occurred: "Found incompatible module".
remote:        info If you think this is a bug, please open a bug report with the information provided in "/tmp/build_c472d4366cfa53133fe29a2426a45a7b/yarn-error.log".
remote:        info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.
remote:
remote:  !
remote:  !     Precompiling assets failed.
remote:  !
remote:  !     Push rejected, failed to compile Ruby app.
remote:
remote:  !     Push failed

This is my package.json file (in root folder):

{
  "name": "site",
  "private": true,
  "dependencies": {
    "@rails/webpacker": "4.2.2",
    "flatpickr": "^4.6.3",
    "jquery": "^3.3.1",
    "node": "^12.x",
    "node-sass": "^4.13.1",
    "reading-time": "^1.2.0",
    "simple-lightbox": "^2.1.0"
  },
  "devDependencies": {
    "@babel/plugin-syntax-dynamic-import": "^7.8.3",
    "webpack-cli": "^3.3.11",
    "webpack-dev-server": "^3.10.3"
  }
}

node --version:

v13.10.1

heroku run node --version:

Running node --version on ⬢ -site... up, run.4229 (Hobby)
v12.16.1

Answer 1

https://devcenter.heroku.com/articles/deploying-nodejs

You can specify a node version on Heroku via your package.json

{
  "name": "node-example",
  "version": "1.0.0",
  "description": "This example is so cool.",
  "main": "web.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [
    "example",
    "heroku"
  ],
  "author": "jane-doe",
  "license": "MIT",
  "dependencies": {
    "express": "^4.9.8"
  },
  "engines": {
    "node": "10.x"
  }
}

You can find the currently supported node versions here: https://devcenter.heroku.com/articles/nodejs-support

Answer 2

Not sure exactly what it is, but the issue had something to do with the Heroku buildpack I was using (heroku-buildpack-bundler2)

Here's what I did to solve it:

$ heroku buildpacks:set heroku/ruby
$ heroku buildpacks:add --index 1 heroku/nodejs

$ git push heroku master

All works fine now :-)