Thanks for the information!
OK, I think I got it! Please pull the latest Sparrow project and build the framework again.
The problem was that the "Sparrow.framework" target didn't have 64bit in its "Architectures" project settings; and it was set to "Build Active Architecture only". I changed both of that.
I tested it with a completely new project. With the old ".framework" file, I got your error when I executed "Product / Archive". After the change, that works.
I hope that was the same problem you're seeing — please try it out and let me know! Thanks a lot in advance! =)