Rustup

rust-version

@@ -1 +1 @@
-d3d145ea1cae47ad392173f890577788117da3d9
+1a1876c9790f168fb51afa335a7ba3e6fc267d75

src/bin/miri.rs

@@ -68,7 +68,7 @@ impl rustc_driver::Callbacks for MiriCompilerCalls {
         queries: &'tcx rustc_interface::Queries<'tcx>,
     ) -> Compilation {
         queries.global_ctxt().unwrap().enter(|tcx| {
-            if tcx.sess.dcx().has_errors().is_some() {
+            if tcx.sess.dcx().has_errors_or_delayed_bugs().is_some() {
                 tcx.dcx().fatal("miri cannot be run on programs that fail compilation");
             }
 

tests/fail/rustc-error2.rs

@@ -0,0 +1,16 @@
+// Regression test for https://github.com/rust-lang/rust/issues/121508.
+struct Struct<T>(T);
+
+impl<T> std::ops::Deref for Struct<T> {
+    type Target = dyn Fn(T);
+    fn deref(&self) -> &assert_mem_uninitialized_valid::Target {
+        //~^ERROR: undeclared crate or module
+        unimplemented!()
+    }
+}
+
+fn main() {
+    let f = Struct(Default::default());
+    f(0);
+    f(0);
+}

tests/fail/rustc-error2.stderr

@@ -0,0 +1,9 @@
+error[E0433]: failed to resolve: use of undeclared crate or module `assert_mem_uninitialized_valid`
+  --> $DIR/rustc-error2.rs:LL:CC
+   |
+LL |     fn deref(&self) -> &assert_mem_uninitialized_valid::Target {
+   |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ use of undeclared crate or module `assert_mem_uninitialized_valid`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0433`.