error[E0603]: unit struct `Root` is private
  --> tests/trybuild/fail/owner_root_not_constructible.rs:11:39
   |
11 |     let _root = api::topic::internal::Root;
   |                                       ^^^^ private unit struct
   |
note: the unit struct `Root` is defined here
  --> $WORKSPACE/phoxal-api/src/lib.rs
   |
   |   phoxal_api_tree! {
   |  _-^^^^^^^^^^^^^^^
   | |     version y2026_1 {
   | |         drive {
   | |             /// Why actuation authority is in its current state.
...  |
   | | }
   | |_- cannot be constructed because it is `#[non_exhaustive]`
   = note: this error originates in the macro `phoxal_api_tree` (in Nightly builds, run with -Z macro-backtrace for more info)
