From a5ba75283e279205dd96d402dfde42041ac53fb4 Mon Sep 17 00:00:00 2001
From: Mark Rousskov <mark.simulacrum@gmail.com>
Date: Sun, 10 May 2020 16:53:48 -0400
Subject: [PATCH] Fail if I/O error occurs during testing

---
 src/tools/compiletest/src/main.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/tools/compiletest/src/main.rs b/src/tools/compiletest/src/main.rs
index 3a8a5491255a0..93a414ff6b9f3 100644
--- a/src/tools/compiletest/src/main.rs
+++ b/src/tools/compiletest/src/main.rs
@@ -347,7 +347,10 @@ pub fn run_tests(config: Config) {
         Ok(true) => {}
         Ok(false) => panic!("Some tests failed"),
         Err(e) => {
-            println!("I/O failure during tests: {:?}", e);
+            // We don't know if tests passed or not, but if there was an error
+            // during testing we don't want to just suceeed (we may not have
+            // tested something), so fail.
+            panic!("I/O failure during tests: {:?}", e);
         }
     }
 }