Heroku does not read node version

Question

I have a Node project that I want to host on Heroku. I have explicitly defined node and npm versions in my package.json (located in the root directory), which looks like this:

{
  "name": "*********",
  "version": "0.0.0",
  "private": true,
  "engines": {
    "node": "0.12.x",
    "npm": "2.5.x"
  },
  "scripts": {
    "start": "node ./bin/www"
  },
  "dependencies": {
    "body-parser": "^1.13.3",
    ...
}

However, when I try to push the app to heroku

git push heroku master 

Heroku tries to build the app, but it seems like it's not able to read the node and npm versions. Here is the response I get.

remote: -----> Installing binaries
remote:        engines.node (package.json):  unspecified
remote:        engines.npm (package.json):   unspecified (use default)
remote:         
remote:        Resolving node version (latest stable) via semver.io...
remote:        Downloading and installing node 4.2.1...
remote:        Using default npm version: 2.14.7

Why does heroku not read the node and npm version from package.json?

Answer 1

@rdegges was right that the package.json wasn't correctly committed to Heroku. So just following the Heroku instructions didn't work for me for some reason. Here is what I had to do in order to make it work.

git clone <my git project>
heroku create <app name>

#remove package.json
mv package.json tmp_package.json
git add package.json
git commit -m "removed package.json"

#re-add package.json
mv tmp_package.json package.json
git add package.json
git commit -m "re-added package.json"

git push heroku master