diff --git a/rust-version b/rust-version
index cc0787f877e..feed920a166 100644
--- a/rust-version
+++ b/rust-version
@@ -1 +1 @@
-nightly-2018-10-22
+nightly-2018-10-29
diff --git a/src/lib.rs b/src/lib.rs
index ed23eef3f55..a93a48cb09d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -181,7 +181,7 @@ pub fn eval_main<'a, 'tcx: 'a>(
                 let e = e.to_string();
                 let msg = format!("constant evaluation error: {}", e);
                 let mut err = struct_error(ecx.tcx.tcx.at(span), msg.as_str());
-                let (frames, span) = ecx.generate_stacktrace(None);
+                let frames = ecx.generate_stacktrace(None);
                 err.span_label(span, e);
                 for FrameInfo { span, location, .. } in frames {
                     err.span_note(span, &format!("inside call to `{}`", location));