How to download native libraries for all available OS?

[hmf]

I would like to download all dependency artifacts for all of the available OS. The goal is to generate a fat Jar that can be executed in any OS. I am experimenting with Coursier and the following is working:

  // OpenFX/JavaFX libraries
  val javaFXModuleNames = Seq(BASE_, CONTROLS_, FXML_, GRAPHICS_, MEDIA_, SWING_, WEB_)

  override def unmanagedClasspath: Target[Loose.Agg[PathRef]] = T{
    import coursier._
    import coursier.parse.DependencyParser

    val controlsFXModule = dep"org.controlsfx:controlsfx:11.1.0"

    // Generate the dependencies
    val javaFXModules = javaFXModuleNames.map(
      m => Dependency(Module(org"org.openjfx", ModuleName(s"javafx-$m")), javaFXVersion)
    ) ++
      Seq(controlsFXModule)

    val files = Fetch().addDependencies(javaFXModules: _*).run()
    val pathRefs = files.map(f => PathRef(os.Path(f)))
    Agg(pathRefs : _*)
  }

The command:

$ ./mill show unmanaged.unmanagedClasspath

produces:

[1/1] show 
[1/1] show > [1/1] unmanaged.unmanagedClasspath 
[
  "ref:ddef4c4b:/home/hmf/.cache/coursier/v1/https/repo1.maven.org/maven2/org/openjfx/javafx-base/16/javafx-base-16.jar",
  "ref:d150f068:/home/hmf/.cache/coursier/v1/https/repo1.maven.org/maven2/org/openjfx/javafx-controls/16/javafx-controls-16.jar",
  "ref:c6d45ef4:/home/hmf/.cache/coursier/v1/https/repo1.maven.org/maven2/org/openjfx/javafx-fxml/16/javafx-fxml-16.jar",
  "ref:19dc6267:/home/hmf/.cache/coursier/v1/https/repo1.maven.org/maven2/org/openjfx/javafx-graphics/16/javafx-graphics-16.jar",
  "ref:e42f9c9c:/home/hmf/.cache/coursier/v1/https/repo1.maven.org/maven2/org/openjfx/javafx-media/16/javafx-media-16.jar",
  "ref:945374cf:/home/hmf/.cache/coursier/v1/https/repo1.maven.org/maven2/org/openjfx/javafx-swing/16/javafx-swing-16.jar",
  "ref:406062e3:/home/hmf/.cache/coursier/v1/https/repo1.maven.org/maven2/org/openjfx/javafx-web/16/javafx-web-16.jar",
  "ref:5fa6aaf7:/home/hmf/.cache/coursier/v1/https/repo1.maven.org/maven2/org/controlsfx/controlsfx/11.1.0/controlsfx-11.1.0.jar",
  "ref:3df5678c:/home/hmf/.cache/coursier/v1/https/repo1.maven.org/maven2/org/openjfx/javafx-base/16/javafx-base-16-linux.jar",
  "ref:0bc3d56f:/home/hmf/.cache/coursier/v1/https/repo1.maven.org/maven2/org/openjfx/javafx-controls/16/javafx-controls-16-linux.jar",
  "ref:2b46ca60:/home/hmf/.cache/coursier/v1/https/repo1.maven.org/maven2/org/openjfx/javafx-fxml/16/javafx-fxml-16-linux.jar",
  "ref:e0c0bcbc:/home/hmf/.cache/coursier/v1/https/repo1.maven.org/maven2/org/openjfx/javafx-graphics/16/javafx-graphics-16-linux.jar",
  "ref:c7238720:/home/hmf/.cache/coursier/v1/https/repo1.maven.org/maven2/org/openjfx/javafx-media/16/javafx-media-16-linux.jar",
  "ref:a9caa1a4:/home/hmf/.cache/coursier/v1/https/repo1.maven.org/maven2/org/openjfx/javafx-swing/16/javafx-swing-16-linux.jar",
  "ref:8b0370d7:/home/hmf/.cache/coursier/v1/https/repo1.maven.org/maven2/org/openjfx/javafx-web/16/javafx-web-16-linux.jar"
]

How can I tell Mill to also download the native Windows and MacOS JARs?

TIA