add convoluted test for issue 132920

tests/run-make/diagnostics-traits-from-duplicate-crates/minibevy.rs

@@ -0,0 +1,2 @@
+pub trait Resource {}
+pub struct Ray2d;

tests/run-make/diagnostics-traits-from-duplicate-crates/minirapier.rs

@@ -0,0 +1 @@
+pub type Ray = minibevy::Ray2d;

tests/run-make/diagnostics-traits-from-duplicate-crates/repro.rs

@@ -0,0 +1,14 @@
+extern crate minibevy;
+extern crate minirapier;
+
+use minibevy::Resource;
+use minirapier::Ray;
+
+fn insert_resource<R: Resource>(_resource: R) {}
+
+struct Res;
+impl Resource for Res {}
+
+fn main() {
+    insert_resource(Res.into());
+}

tests/run-make/diagnostics-traits-from-duplicate-crates/rmake.rs

@@ -0,0 +1,45 @@
+// Non-regression test for issue #132920 where multiple versions of the same crate are present in
+// the dependency graph, and an unexpected error in a dependent crate caused an ICE in the
+// unsatisfied bounds diagnostics for traits present in multiple crate versions.
+//
+// Setup:
+// - two versions of the same crate: minibevy_a and minibevy_b
+// - minirapier: depends on minibevy_a
+// - repro: depends on minirapier and minibevy_b
+
+use run_make_support::rustc;
+
+fn main() {
+    // Prepare dependencies, mimicking a check build with cargo.
+    rustc()
+        .input("minibevy.rs")
+        .crate_name("minibevy")
+        .crate_type("lib")
+        .emit("metadata")
+        .metadata("a")
+        .extra_filename("-a")
+        .run();
+    rustc()
+        .input("minibevy.rs")
+        .crate_name("minibevy")
+        .crate_type("lib")
+        .emit("metadata")
+        .metadata("b")
+        .extra_filename("-b")
+        .run();
+    rustc()
+        .input("minirapier.rs")
+        .crate_name("minirapier")
+        .crate_type("lib")
+        .emit("metadata")
+        .extern_("minibevy", "libminibevy-a.rmeta")
+        .run();
+
+    // Building the main crate used to ICE here when printing the `type annotations needed` error.
+    rustc()
+        .input("repro.rs")
+        .extern_("minibevy", "libminibevy-b.rmeta")
+        .extern_("minirapier", "libminirapier.rmeta")
+        .run_fail()
+        .assert_stderr_not_contains("error: the compiler unexpectedly panicked. this is a bug");
+}