From 9a741d13b9ca848548f29ef65672ddf4b1889df1 Mon Sep 17 00:00:00 2001
From: Who? Me?! <mark-i-m@users.noreply.github.com>
Date: Mon, 22 Oct 2018 12:48:58 -0500
Subject: [PATCH] Add a note on bisecting

---
 src/compiler-debugging.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/compiler-debugging.md b/src/compiler-debugging.md
index d1171e0e..aca7f742 100644
--- a/src/compiler-debugging.md
+++ b/src/compiler-debugging.md
@@ -384,3 +384,7 @@ create a minimal working example with Godbolt. Go to
 
 
 [env-logger]: https://docs.rs/env_logger/0.4.3/env_logger/
+
+## Narrowing (Bisecting) Regressions
+
+The [cargo-bisect-rustc](https://github.com/rust-lang-nursery/cargo-bisect-rustc) tool can be used as a quick and easy way to find exactly which PR caused a change in `rustc` behavior. It automatically downloads `rustc` PR artifacts and tests them against a project you provide until it finds the regression. You can then look at the PR to get more context on *why* it was changed.  See [this tutorial](https://github.com/rust-lang-nursery/cargo-bisect-rustc/blob/master/TUTORIAL.md) on how to use it.