What do setting do I use for xcode-select -switch?
Did you install xcode or just the command line tools?
I installed just the command line tools and was able to trick some GEMS by using the following command:
sudo xcode-select -switch /usr/binI basically pointed them to the bin folder where my GCC lives.
sudo xcode-select -switch /Applications/Xcode.app/Contents/Developersolved for me