When running jpackage with version 4.0.0, the application JVM arguments are missing from the Application.cfg file, and thereby the application, which fails to start.

Windows:
jpackage/Application/app/Application.cfg

Linux:
jpackage/Application/lib/app/Application.cfg

build.gradle

application {
    mainClass = "application.package.MainClass"
    mainModule = "module.name"
    applicationDefaultJvmArgs = [
            "-Djdbc.url=jdbc:oracle:thin:@database.host.name:1521:dbname"
    ]
}

The jlink/jpackage configuration is quite simple, I can add that if required.

3.1.3:

[Application]
app.mainmodule=module.name/application.package.MainClass

[JavaOptions]
java-options=-Djpackage.app-version=1.0.8
java-options=-Djdbc.url=jdbc:oracle:thin:@database.host.name:1521:dbname

4.0.0:

[Application]
app.mainmodule=module.name/application.package.MainClass

[JavaOptions]
java-options=-Djpackage.app-version=1.0.8

As far as I can tell the jlink output is the same.

ps. huge thanks for maintaining this plugin, its has proved absolutely essential!