One thing that I noticed when using Coda 2 is that the ‘Compare’ option did not seem to do anything. No message just… nothing. Someone on the Coda Users group had an answer. Apparently it is an issue with upgrading from xCode 4.2 to 4.3:
Sounds like you need to update your machines Xcode path. On machines that have gone from Xcode 4.2 to 4.3, this doesn’t get automatically updated to deal with the moving of everything into the Xcode application bundle.
>>sudo xcode-select -switch /Applications/Xcode.app
Thanks to Scott Denowh in the Coda Users forum for this fix. It is working fine for me now.