error: `extern` block uses type `AliasB`, which is not FFI-safe --> $DIR/opaque-ty-ffi-normalization-cycle.rs:37:21 | LL | fn lint_me() -> ::Assoc; | ^^^^^^^^^^^^^^^^^^^^^^^^^ not FFI-safe | = note: opaque types have no C equivalent note: the lint level is defined here --> $DIR/opaque-ty-ffi-normalization-cycle.rs:3:9 | LL | #![deny(improper_ctypes)] | ^^^^^^^^^^^^^^^ error: aborting due to 1 previous error