1 files changed, 16 insertions, 0 deletions

diff --git a/tests/ui/issues/issue-20772.stderr b/tests/ui/issues/issue-20772.stderr
new file mode 100644
index 000000000..22b9f5bd4
--- /dev/null
+++ b/tests/ui/issues/issue-20772.stderr
@@ -0,0 +1,16 @@
+error[E0391]: cycle detected when computing the super traits of `T` with associated type name `Item`
+  --> $DIR/issue-20772.rs:1:1
+   |
+LL | trait T : Iterator<Item=Self::Item>
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: ...which immediately requires computing the super traits of `T` with associated type name `Item` again
+note: cycle used when computing the super traits of `T`
+  --> $DIR/issue-20772.rs:1:1
+   |
+LL | trait T : Iterator<Item=Self::Item>
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0391`.