From 4af417a78a1684e2c75b275ee3a0db8049ef8b0f Mon Sep 17 00:00:00 2001
From: Henry Boisdequin <65845077+henryboisdequin@users.noreply.github.com>
Date: Tue, 9 Feb 2021 18:43:39 +0530
Subject: add suggestion to use the `async_recursion` crate

---
 compiler/rustc_typeck/src/check/check.rs | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'compiler')

diff --git a/compiler/rustc_typeck/src/check/check.rs b/compiler/rustc_typeck/src/check/check.rs
index ab3c26fac83..f0bc31641b4 100644
--- a/compiler/rustc_typeck/src/check/check.rs
+++ b/compiler/rustc_typeck/src/check/check.rs
@@ -1446,6 +1446,9 @@ fn async_opaque_type_cycle_error(tcx: TyCtxt<'tcx>, span: Span) {
     struct_span_err!(tcx.sess, span, E0733, "recursion in an `async fn` requires boxing")
         .span_label(span, "recursive `async fn`")
         .note("a recursive `async fn` must be rewritten to return a boxed `dyn Future`")
+        .note(
+            "consider using the `async_recursion` crate: https://crates.io/crates/async_recursion",
+        )
         .emit();
 }
 
-- 
cgit 1.4.1-3-g733a5