Why I am getting Could not find multi_json-1.3.1 in any of the sources?

Question

I have a simple Rails application I want to deploy to Heroku. When I run the below command

git push heroku master

The below error message is di

Answer 1

For me this was caused because Pow (local rack server) was not using the correct RVM ruby version/gemset.

Fixed by adding the following .powrc:

# based on https://coderwall.com/p/pkj39a
if [ -f "$rvm_path/scripts/rvm" ] && [ -f ".ruby-version" ] && [ -f ".ruby-gemset" ]; then
  source "$rvm_path/scripts/rvm"
  rvm use `cat .ruby-version`@`cat .ruby-gemset`
fi

Source: https://coderwall.com/p/pkj39a