From 44a4fd8b92362073652705ea7e1b7dc5559d6d1c Mon Sep 17 00:00:00 2001
From: cushon <cushon@google.com>
Date: Wed, 6 Feb 2019 09:34:50 -0800
Subject: [PATCH] Improve a precondition failure message

PiperOrigin-RevId: 232689469
---
 .../java/com/google/devtools/build/lib/analysis/Runfiles.java  | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/Runfiles.java b/src/main/java/com/google/devtools/build/lib/analysis/Runfiles.java
index 477764e9bd63db..4ca156a02b6fe7 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/Runfiles.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/Runfiles.java
@@ -1115,7 +1115,8 @@ private Builder merge(Runfiles runfiles, boolean includeUnconditionalArtifacts,
       }
       // The suffix should be the same within any blaze build, except for the EMPTY runfiles, which
       // may have an empty suffix, but that is covered above.
-      Preconditions.checkArgument(suffix.equals(runfiles.suffix));
+      Preconditions.checkArgument(
+          suffix.equals(runfiles.suffix), "%s != %s", suffix, runfiles.suffix);
       if (includeUnconditionalArtifacts) {
         artifactsBuilder.addTransitive(runfiles.getUnconditionalArtifacts());
       }