Consider this code in a crate's lib.rs:

mod m1 { pub mod m2 { pub struct Foo; } } pub use m1::*; use crate::m1::m2;

The generated documentation will show the m2 module at the crate root, though nothing will show up inside the m2 module page. The m2 module is private to outside crates, so I don't think it should be showing up at all.

Meta

rustc --version --verbose:

rustc 1.36.0-nightly (7d5aa43 2019-05-16)
binary: rustc
commit-hash: 7d5aa43
commit-date: 2019-05-16
host: x86_64-pc-windows-msvc
release: 1.36.0-nightly
LLVM version: 8.0