error[E0433]: failed to resolve: maybe a missing crate `clippy`?
  --> $DIR/tool-mod-child.rs:2:5
   |
LL | use clippy::a::b;
   |     ^^^^^^ maybe a missing crate `clippy`?
   |
   = help: consider adding `extern crate clippy` to use the `clippy` crate

error[E0432]: unresolved import `clippy`
  --> $DIR/tool-mod-child.rs:1:5
   |
LL | use clippy::a;
   |     ^^^^^^ maybe a missing crate `clippy`?
   |
   = help: consider adding `extern crate clippy` to use the `clippy` crate

error[E0433]: failed to resolve: maybe a missing crate `rustdoc`?
  --> $DIR/tool-mod-child.rs:5:5
   |
LL | use rustdoc::a::b;
   |     ^^^^^^^ maybe a missing crate `rustdoc`?
   |
   = help: consider adding `extern crate rustdoc` to use the `rustdoc` crate

error[E0432]: unresolved import `rustdoc`
  --> $DIR/tool-mod-child.rs:4:5
   |
LL | use rustdoc::a;
   |     ^^^^^^^ maybe a missing crate `rustdoc`?
   |
   = help: consider adding `extern crate rustdoc` to use the `rustdoc` crate

error: aborting due to 4 previous errors

Some errors have detailed explanations: E0432, E0433.
For more information about an error, try `rustc --explain E0432`.