2 files changed, 31 insertions, 0 deletions
diff --git a/tests/ui-fulldeps/internal-lints/import-of-type-ir-traits.rs b/tests/ui-fulldeps/internal-lints/import-of-type-ir-traits.rs
new file mode 100644
index 00000000000..3fdd65d6c87
--- /dev/null
+++ b/tests/ui-fulldeps/internal-lints/import-of-type-ir-traits.rs
@@ -0,0 +1,16 @@
+//@ compile-flags: -Z unstable-options
+//@ ignore-stage1
+
+#![feature(rustc_private)]
+#![deny(rustc::usage_of_type_ir_traits)]
+
+extern crate rustc_type_ir;
+
+use rustc_type_ir::Interner;
+
+fn foo<I: Interner>(cx: I, did: I::DefId) {
+    let _ = cx.trait_is_unsafe(did);
+    //~^ ERROR do not use `rustc_type_ir::Interner` or `rustc_type_ir::InferCtxtLike` unless you're inside of the trait solver
+}
+
+fn main() {}
diff --git a/tests/ui-fulldeps/internal-lints/import-of-type-ir-traits.stderr b/tests/ui-fulldeps/internal-lints/import-of-type-ir-traits.stderr
new file mode 100644
index 00000000000..df29a494558
--- /dev/null
+++ b/tests/ui-fulldeps/internal-lints/import-of-type-ir-traits.stderr
@@ -0,0 +1,15 @@
+error: do not use `rustc_type_ir::Interner` or `rustc_type_ir::InferCtxtLike` unless you're inside of the trait solver
+  --> $DIR/import-of-type-ir-traits.rs:12:13
+   |
+LL |     let _ = cx.trait_is_unsafe(did);
+   |             ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: the method or struct you're looking for is likely defined somewhere else downstream in the compiler
+note: the lint level is defined here
+  --> $DIR/import-of-type-ir-traits.rs:5:9
+   |
+LL | #![deny(rustc::usage_of_type_ir_traits)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+