From f7063657498cd37a7633c6570ee953aaab616a6c Mon Sep 17 00:00:00 2001
From: Jonathan Behrens <fintelia@gmail.com>
Date: Sat, 8 Jun 2019 19:11:04 -0400
Subject: [PATCH] Changes to config.toml require a clean

---
 src/how-to-build-and-run.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/how-to-build-and-run.md b/src/how-to-build-and-run.md
index f44179bc..92fbcb0f 100644
--- a/src/how-to-build-and-run.md
+++ b/src/how-to-build-and-run.md
@@ -41,6 +41,9 @@ codegen-units = 0
 debug = true
 ```
 
+If you have already built `rustc`, then you may have to execute `rm -rf build` for subsequent
+configuration changes to take effect.
+
 ### What is `x.py`?
 
 `x.py` is the script used to orchestrate the tooling in the `rustc` repository.