From c8e58512d4ad327cdc974b6bfbde62e2778f0cc3 Mon Sep 17 00:00:00 2001
From: Niko Matsakis <niko@alum.mit.edu>
Date: Wed, 2 Oct 2019 09:10:06 -0400
Subject: [PATCH] improved debug output

---
 src/librustc_typeck/check/closure.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/librustc_typeck/check/closure.rs b/src/librustc_typeck/check/closure.rs
index cac94bec6428..27f1a4aac61d 100644
--- a/src/librustc_typeck/check/closure.rs
+++ b/src/librustc_typeck/check/closure.rs
@@ -595,6 +595,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     ) -> ty::PolyFnSig<'tcx> {
         let astconv: &dyn AstConv<'_> = self;
 
+        debug!(
+            "supplied_sig_of_closure(decl={:?}, body.generator_kind={:?})",
+            decl,
+            body.generator_kind,
+        );
+
         // First, convert the types that the user supplied (if any).
         let supplied_arguments = decl.inputs.iter().map(|a| astconv.ast_ty_to_ty(a));
         let supplied_return = match decl.output {