diff --git a/gcc/rust/ast/rust-ast.cc b/gcc/rust/ast/rust-ast.cc
index 003a6edbc10..ed4b92e8b95 100644
--- a/gcc/rust/ast/rust-ast.cc
+++ b/gcc/rust/ast/rust-ast.cc
@@ -3363,7 +3363,13 @@ void
 Module::process_file_path ()
 {
   rust_assert (kind == Module::ModuleKind::UNLOADED);
-  rust_assert (module_file.empty ());
+
+  if (!module_file.empty ())
+    {
+      rust_error_at (locus, "error handling module file for %qs",
+		     module_name.as_string ().c_str ());
+      return;
+    }
 
   // This corresponds to the path of the file 'including' the module. So the
   // file that contains the 'mod <file>;' directive
diff --git a/gcc/testsuite/rust/compile/issue-4145.rs b/gcc/testsuite/rust/compile/issue-4145.rs
new file mode 100644
index 00000000000..98b33cade11
--- /dev/null
+++ b/gcc/testsuite/rust/compile/issue-4145.rs
@@ -0,0 +1,13 @@
+// { dg-excess-errors "warnings" }
+
+struct S {
+    field: [u8; {
+        #[path = "outer/inner.rs"]
+        // { dg-warning "error handling module file for .inner." "#4145" { xfail *-*-* } .+1 }
+        mod inner;
+        // OK
+        0
+    }],
+}
+
+fn main() {}