src/java.base/share/classes/java/lang/System.java

@@ -1917,11 +1917,11 @@
         System.bootLayer = ModuleBootstrap.boot();
 
         // base module needs to be loose
         Module base = Object.class.getModule();
         if (base == null)
-            throw new InternalError();
+            throw new InternalError("base module is null");
         Modules.addReads(base, null);
 
         // module system initialized
         VM.initLevel(2);
     }