Error when trying to install app with mysql2 gem

Question

Im trying to install an open source rails 3.2.21 application that uses the mysql2 gem, but when i try and run the bundle commant I get the followin

Answer 1

The solution for me was to install the Xcode Command Line Tools.

I had recently updated Xcode through the Mac App Store, and every time I do that, I've found that I have to reinstall the Command Line Tools again.

xcode-select --install