From 4fe306f5c39c6f488e13b7c3de1ccab586375289 Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Fri, 15 Dec 2023 09:25:24 -0800
Subject: [PATCH] Restore UI test involving missing Display impl

This test existed prior to 04b91d76462834279a323b7771b48158aba19db4.

Since 791a98eb93e08f111bd16d7ec73caf50f7225f31, we can rely on rust-src being installed.
---
 tests/ui/missing-display.rs     | 9 +++++++++
 tests/ui/missing-display.stderr | 8 ++++++++
 2 files changed, 17 insertions(+)
 create mode 100644 tests/ui/missing-display.rs
 create mode 100644 tests/ui/missing-display.stderr

diff --git a/tests/ui/missing-display.rs b/tests/ui/missing-display.rs
new file mode 100644
index 0000000..31e23fe
--- /dev/null
+++ b/tests/ui/missing-display.rs
@@ -0,0 +1,9 @@
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum MyError {
+    First,
+    Second,
+}
+
+fn main() {}
diff --git a/tests/ui/missing-display.stderr b/tests/ui/missing-display.stderr
new file mode 100644
index 0000000..8dea6c5
--- /dev/null
+++ b/tests/ui/missing-display.stderr
@@ -0,0 +1,8 @@
+error[E0277]: `MyError` doesn't implement `std::fmt::Display`
+  --> tests/ui/missing-display.rs:4:1
+   |
+4  | pub enum MyError {
+   | ^^^^^^^^^^^^^^^^ `MyError` cannot be formatted with the default formatter
+   |
+   = help: the trait `std::fmt::Display` is not implemented for `MyError`
+   = note: in format strings you may be able to use `{:?}` (or {:#?} for pretty-print) instead