Fix #74081 and add the test case from #74236

src/librustc_middle/ty/print/pretty.rs

@@ -393,7 +393,7 @@ pub trait PrettyPrinter<'tcx>:
                     .tcx()
                     .item_children(visible_parent)
                     .iter()
-                    .find(|child| child.res.def_id() == def_id)
+                    .find(|child| child.res.opt_def_id() == Some(def_id))
                     .map(|child| child.ident.name);
                 if let Some(reexport) = reexport {
                     *name = reexport;

src/test/ui/issues/issue-74236/auxiliary/dep.rs

@@ -0,0 +1,8 @@
+// edition:2018
+
+mod private { pub struct Pub; }
+
+// Reexport built-in attribute without a DefId (requires Rust 2018).
+pub use cfg_attr as attr;
+// This export needs to be after the built-in attribute to trigger the bug.
+pub use private::Pub as Renamed;

src/test/ui/issues/issue-74236/main.rs

@@ -0,0 +1,9 @@
+// edition:2018
+// aux-build:dep.rs
+// compile-flags:--extern dep
+
+fn main() {
+    // Trigger an error that will print the path of dep::private::Pub (as "dep::Renamed").
+    let () = dep::Renamed;
+    //~^ ERROR mismatched types
+}

src/test/ui/issues/issue-74236/main.stderr

@@ -0,0 +1,11 @@
+error[E0308]: mismatched types
+  --> $DIR/main.rs:7:9
+   |
+LL |     let () = dep::Renamed;
+   |         ^^   ------------ this expression has type `dep::Renamed`
+   |         |
+   |         expected struct `dep::Renamed`, found `()`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0308`.