--- old/test/hotspot/jtreg/compiler/graalunit/common/GraalUnitTestLauncher.java	2019-01-11 10:25:41.167000899 +0100
+++ new/test/hotspot/jtreg/compiler/graalunit/common/GraalUnitTestLauncher.java	2019-01-11 10:25:40.975096901 +0100
@@ -239,6 +239,8 @@
         javaFlags.add("-Djava.awt.headless=true");
         javaFlags.add("-esa");
         javaFlags.add("-ea");
+        // Make sure exception message is never null
+        javaFlags.add("-XX:-OmitStackTraceInFastThrow");
 
 
         // generate class path