error[E0391]: cycle detected when computing layout of `S<S<()>>`
   |
   = note: ...which requires computing layout of `<S<()> as Tr>::I`...
   = note: ...which again requires computing layout of `S<S<()>>`, completing the cycle
   = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information

error: post-monomorphization error: a cycle occurred during layout computation
  --> RUSTLIB/core/src/mem/mod.rs:LL:CC
   |
LL |     intrinsics::size_of::<T>()
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ post-monomorphization error occurred here
   |
   = note: BACKTRACE:
   = note: inside `std::mem::size_of::<S<S<()>>>` at RUSTLIB/core/src/mem/mod.rs:LL:CC
note: inside `foo::<S<()>>`
  --> tests/fail/layout_cycle.rs:LL:CC
   |
LL |     mem::size_of::<S<T>>()
   |     ^^^^^^^^^^^^^^^^^^^^^^
note: inside `main`
  --> tests/fail/layout_cycle.rs:LL:CC
   |
LL |     println!("{}", foo::<S<()>>());
   |                    ^^^^^^^^^^^^^^

note: some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0391`.