1 error[E0391]: unsupported cyclic reference between types/traits detected
3 note: the cycle begins when computing layout of `S`...
4 note: ...which then requires computing layout of `std::option::Option<<S as Mirror>::It>`...
5 note: ...which then requires computing layout of `<S as Mirror>::It`...
6 = note: ...which then again requires computing layout of `S`, completing the cycle.
8 error: aborting due to previous error