From 4d4d1592c732a22577dba8c8fbf304e6240e25d8 Mon Sep 17 00:00:00 2001
From: Alex Butler <alexheretic@gmail.com>
Date: Tue, 29 May 2018 00:18:57 +0100
Subject: [PATCH] Add mercy for devs that run `cargo test` without building

---
 src/test/mod.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/test/mod.rs b/src/test/mod.rs
index d5c0533fde6..e589b69ec2e 100644
--- a/src/test/mod.rs
+++ b/src/test/mod.rs
@@ -900,6 +900,10 @@ fn rustfmt() -> PathBuf {
     me.pop(); // chop of the test name
     me.pop(); // chop off `deps`
     me.push("rustfmt");
+    assert!(
+        me.is_file(),
+        "no rustfmt bin, try running `cargo build` before testing"
+    );
     return me;
 }