I upgraded from Xcode 7.3.1 to Xcode 8.1 and chose Swift 2.3 migration. Now my unit tests won't compile, it fails on the import, specifically No such module 'Foo' where Foo is the module name.
"Enable Testability" is already set to Yes. I have "Use Legacy Swift Language Version" set to Yes for both the project and target. I've tried clean, delete DerivedData and rebuild.