libc++abi.dylib: terminating with uncaught exception of type NSException (lldb)

In Xcode 9 and Swift 4:

Print exception stack to know the reason of the exception:

1. Go to show break point navigator.

2. Add (+) Add Exception Breakpoint.

3. Select the new breakpoint, Control-Click, Edit Breakpoint.

4. Add Action and Enter: po $arg1