IAE while invoking javadoc with --patch-module

Run from attached project
javadoc --module-source-path src --patch-module m1=patch --module-path modules --module m2

java.lang.IllegalArgumentException
        at jdk.compiler/com.sun.tools.javac.main.OptionHelper$GrumpyHelper.handleFileManagerOption(OptionHelper.java:111)
        at jdk.compiler/com.sun.tools.javac.main.Option.process(Option.java:1041)
        at jdk.compiler/com.sun.tools.javac.main.Option$7.process(Option.java:208)
        at jdk.javadoc/jdk.javadoc.internal.tool.ToolOption$25.process(ToolOption.java:224)
        at jdk.javadoc/jdk.javadoc.internal.tool.Start.parseArgs(Start.java:603)
        at jdk.javadoc/jdk.javadoc.internal.tool.Start.parseAndExecute(Start.java:349)
        at jdk.javadoc/jdk.javadoc.internal.tool.Start.begin(Start.java:295)
        at jdk.javadoc/jdk.javadoc.internal.tool.Start.begin(Start.java:239)
        at jdk.javadoc/jdk.javadoc.internal.tool.Main.execute(Main.java:63)
        at jdk.javadoc/jdk.javadoc.internal.tool.Main.main(Main.java:52)
javadoc: error - fatal exception
1 error