--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/util/RawDiagnosticFormatter.java	Tue Aug 28 09:01:54 2018 +0200
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/util/RawDiagnosticFormatter.java	Wed Aug 29 09:36:17 2018 +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);
         }