Can't install JSON gem

Question

I need to install json because I get this error:

Could not find json-1.4.6 in any of the sources

I ran gem install json and b

Answer 1

After checking logs by running $ heroku logs

I found "An error occurred while installing json (1.4.6), and Bundler cannot continue. Make sure that gem install json -v '1.4.6' succeeds before bundling."

I then removed 2 json entries from the Gemfile.lock and had no further issues.