mysql driver is no longer bundled w/ rails. you'll need to install it yourself w/ sudo gem install mysql however, on ubuntu (heron) this won't work. issue these commands first sudo apt-get install libmysql-ruby libmysqlclient-dev if libmysqlclient-dev...

If you want to get version information about a gem the easiest way to do it is with this command gem list For example gem list activemerchant will output the activemerchant versions I have installed. You can pass only part of the name like gem list ...

Fixtures in Rails allow you to quickly and easily populate a database with sample data. They are great when testing your app and you need to test against a condition that will rely on a certain preexisting data point. Fixtures are located in your RAILS_R...

I just got a new machine and downloaded XCode. I used git to clone my ReactNative project from Github. I have everything ready to go. But when I run `react-native run-ios` I see xcrun: error: unable to find utility "instruments", not a developer tool ...

This actually has more to do with Rails and/or Sinatra than it does with Heroku. You have to enable IFrame support in your headers explicitly. With Rails you can add this to your config/application.rb file config.action_dispatch.default_headers = ...