I\'m a complete n00b on Rails with only beginner knowledge of Ruby. I plan on studying Ruby more before I really learn Rails, but I\'m waayy too curious for my own good.
For me it helped to put version after gem 'sqlite3' in gemfile, so it became gem 'sqlite3', '1.3.7'.
Previously I tried to compile sqlite3, updated gem, etc... Rails wasn't able to "accept" it still, so finally defining the version helped.