Not an issue, the expected value is different (because you didn't use markdown formatting they look the same in this post, the second one has one space more).

Would it need to be a delete to avoid leak of memory?

Probably that you're trying to use something that the kata's Swift version doesn't allow. That or you're doing something wrong, have you googled what that error means?

String' does not conform to protocol 'SequenceType'?
What does that mean? I keep getting that error in Swift.