error: `submodule` may only be specified once (it is implicitly always specified for nested modules)
 --> tests/ui/duplicate_pymodule_submodule.rs:4:2
  |
4 |     mod submod {}
  |     ^^^

error[E0425]: cannot find value `_PYO3_DEF` in module `submod`
 --> tests/ui/duplicate_pymodule_submodule.rs:1:1
  |
1 | #[pyo3::pymodule]
  | ^^^^^^^^^^^^^^^^^ not found in `submod`
  |
  = note: this error originates in the attribute macro `pyo3::pymodule` (in Nightly builds, run with -Z macro-backtrace for more info)
help: consider importing this static
  |
3 +     use crate::mymodule::_PYO3_DEF;
  |