--- old/src/jdk.compiler/share/classes/com/sun/tools/javac/util/RawDiagnosticFormatter.java	2018-08-03 14:07:30.714792379 +0200
+++ new/src/jdk.compiler/share/classes/com/sun/tools/javac/util/RawDiagnosticFormatter.java	2018-08-03 14:07:30.370792395 +0200
@@ -158,6 +158,8 @@
             s = "@" + rawDiagnosticPosHelper.getPosition((JCExpression)arg);
         } else if (arg instanceof PathFileObject) {
             s = ((PathFileObject) arg).getShortName();
+        } else if (arg instanceof Tag) {
+            s = "compiler.misc.tree.tag." + StringUtils.toLowerCase(((Tag) arg).name());
         } else {
             s = super.formatArgument(diag, arg, null);
         }