KarDoclet.java fails to compile under JDK 13

[cxbrooks]

Under

bash-3.2$ java -version
java version "13.0.2" 2020-01-14
Java(TM) SE Runtime Environment (build 13.0.2+8)
Java HotSpot(TM) 64-Bit Server VM (build 13.0.2+8, mixed mode, sharing)

KarDoclet.java fails to compile

  [compile] Compiling 147 source files to /Users/cxh/src/kepler-build/core/target/classes
  [compile] warning: Supported source version 'RELEASE_6' from annotation processor 'org.netbeans.modules.openide.util.ServiceProviderProcessor' less than -source '13'
  [compile] warning: Supported source version 'RELEASE_6' from annotation processor 'org.netbeans.modules.openide.util.NbBundleProcessor' less than -source '13'
  [compile] warning: Supported source version 'RELEASE_6' from annotation processor 'org.netbeans.modules.openide.util.URLStreamHandlerRegistrationProcessor' less than -source '13'
  [compile] /Users/cxh/src/kepler-build/core/src/org/kepler/kar/KarDoclet.java:37: error: package com.sun.javadoc does not exist
  [compile] import com.sun.javadoc.ClassDoc;
  [compile]                       ^
  [compile] /Users/cxh/src/kepler-build/core/src/org/kepler/kar/KarDoclet.java:38: error: package com.sun.javadoc does not exist
  [compile] import com.sun.javadoc.Doc;
  [compile]                       ^
  [compile] /Users/cxh/src/kepler-build/core/src/org/kepler/kar/KarDoclet.java:39: error: package com.sun.javadoc does not exist
  [compile] import com.sun.javadoc.FieldDoc;
  [compile]                       ^
  [compile] /Users/cxh/src/kepler-build/core/src/org/kepler/kar/KarDoclet.java:40: error: package com.sun.javadoc does not exist
  [compile] import com.sun.javadoc.RootDoc;
  [compile]                       ^
  [compile] /Users/cxh/src/kepler-build/core/src/org/kepler/kar/KarDoclet.java:41: error: package com.sun.javadoc does not exist
  [compile] import com.sun.javadoc.Tag;
  [compile]                       ^
  [compile] /Users/cxh/src/kepler-build/core/src/org/kepler/kar/KarDoclet.java:42: error: package com.sun.javadoc does not exist
  [compile] import com.sun.javadoc.Type;
  [compile]                       ^
  [compile] /Users/cxh/src/kepler-build/core/src/org/kepler/kar/KarDoclet.java:58: error: cannot find symbol
  [compile]     public static boolean start(RootDoc root) {
  [compile]                                 ^
  [compile]   symbol:   class RootDoc
  [compile]   location: class KarDoclet
  [compile] /Users/cxh/src/kepler-build/core/src/org/kepler/kar/KarDoclet.java:127: error: cannot find symbol
  [compile]     private static void _parseClass(ClassDoc classDoc, boolean printHeader)
  [compile]                                     ^
  [compile]   symbol:   class ClassDoc
  [compile]   location: class KarDoclet
  [compile] /Users/cxh/src/kepler-build/core/src/org/kepler/kar/KarDoclet.java:253: error: cannot find symbol
  [compile]     private static void _parseField(FieldDoc fieldDoc)
  [compile]                                     ^
  [compile]   symbol:   class FieldDoc
  [compile]   location: class KarDoclet
  [compile] /Users/cxh/src/kepler-build/core/src/org/kepler/kar/KarDoclet.java:292: error: cannot find symbol
  [compile]     private static String _getAndCombineTags(String tag, Doc doc) {
...

Support for the "Old Doclet" was removed, see https://www.oracle.com/java/technologies/javase/13-relnote-issues.html

The solution would be to rewrite KarDoclet to use the newer doclet interface.