why does heroku not list the same gems as i have locally?

I'm still pretty new to heroku and git hub and rails.

My app works locally, but fail开发者_StackOverflows on Heroku. The lines of failure indicate it's because it's missing the plugin I installed locally.

This is a basic question that I can't seem to find. How do I ensure that or update the list of gems on heroku to match my local setup?

I have the gem in my gemfile, and have pushed to git. When I go in heroku console and type gem list it's not there.

Thanks

EDIT. Solved. Can't answer my own question for 24 hours. I had :group => development listed next to the gem. I don't even remember putting that there. Removed it, obviously, and problem solved.

Make sure you run bundle install before pushing to heroku. This generates your Gemfile.lock file that ensures the gems are the same on heroku and locally.

Because Heroku adds some gems to your Gemfile. This is how Heroku works. Take a Rack app. Heroku will add thin to it because that's how they want to run your Rack app. Also they don't install your test and dev gems. Just production.