When trying to document only java.base, causes the following NPE to be thrown.....
onstructing Javadoc information...
java.lang.NullPointerException
at java.util.Collections$UnmodifiableCollection.<init>(java.base@9-internal/Collections.java:1027)
at java.util.Collections$UnmodifiableList.<init>(java.base@9-internal/Collections.java:1303)
at java.util.Collections.unmodifiableList(java.base@9-internal/Collections.java:1290)
at com.sun.tools.javac.code.Symbol$ModuleSymbol.getDirectives(jdk.compiler@9-internal/Symbol.java:953)
at jdk.javadoc.internal.tool.ElementsTable.computeModulePackages(jdk.javadoc@9-internal/ElementsTable.java:582)
at jdk.javadoc.internal.tool.ElementsTable.analyze(jdk.javadoc@9-internal/ElementsTable.java:355)
at jdk.javadoc.internal.tool.JavadocTool.getEnvironment(jdk.javadoc@9-internal/JavadocTool.java:198)
at jdk.javadoc.internal.tool.Start.parseAndExecute(jdk.javadoc@9-internal/Start.java:512)
at jdk.javadoc.internal.tool.Start.begin(jdk.javadoc@9-internal/Start.java:401)
at jdk.javadoc.internal.tool.Start.begin(jdk.javadoc@9-internal/Start.java:345)
at jdk.javadoc.internal.tool.Main.execute(jdk.javadoc@9-internal/Main.java:63)
at jdk.javadoc.internal.tool.Main.main(jdk.javadoc@9-internal/Main.java:52)
javadoc: error - fatal exception
1 error