error[E0603]: module `__seal_t` is private
  --> tests/fail/03-private-by-default.rs:17:1
   |
17 | #[sealed]
   | ^^^^^^^^^ private module
   |
note: the module `__seal_t` is defined here
  --> tests/fail/03-private-by-default.rs:8:17
   |
8  |                 #[sealed]
   |                 ^^^^^^^^^
   = note: this error originates in the attribute macro `sealed` (in Nightly builds, run with -Z macro-backtrace for more info)