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diff --git a/tests/ui/traits/next-solver/assembly/ambiguity-due-to-uniquification-3.rs b/tests/ui/traits/next-solver/assembly/ambiguity-due-to-uniquification-3.rs
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+++ b/tests/ui/traits/next-solver/assembly/ambiguity-due-to-uniquification-3.rs
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+//@ revisions: current next
+//@[next] compile-flags: -Znext-solver
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[current] check-pass
+
+// Regression test from trait-system-refactor-initiative#27.
+//
+// Unlike in the previous two tests, `dyn Object<?x, ?y>: Trait<?x>` relies
+// on structural identity of type inference variables. This inference variable
+// gets constrained to a type containing a region later on. To prevent this
+// from causing an ICE during MIR borrowck, we stash goals which depend on
+// inference variables and then reprove them at the end of HIR typeck.
+
+#![feature(rustc_attrs)]
+#![rustc_no_implicit_bounds]
+trait Trait<T> {}
+impl<T> Trait<T> for () {}
+
+trait Object<T, U>: Trait<T> + Trait<U> {}
+
+#[derive(Clone, Copy)]
+struct Inv<T>(*mut T);
+fn foo<T: Sized, U: Sized>() -> (Inv<dyn Object<T, U>>, Inv<T>) { todo!() }
+fn impls_trait<T: Trait<U>, U>(_: Inv<T>, _: Inv<U>) {}
+
+fn bar() {
+    let (obj, t) = foo();
+    impls_trait(obj, t);
+    //[next]~^ ERROR type annotations needed
+    let _: Inv<dyn Object<&(), &()>> = obj;
+}
+
+fn main() {}