feedback:
On a macOS machine (10.13.6) I tried to create a dmg package:

      $ jpackage -o . --package-type dmg -p lib -m org.openjdk.hello/org.openjdk.hello.Main -n hello

    which gave me the error message

      Exec failed with code 1 command [[/usr/bin/SetFile, -c, icnC, /var/folders/mn/8nt00ldx7dqfrv55wk72mgq80000gr/T/jdk.jpackage9024163201922289964/images/hello/.VolumeIcon.icns] in unspecified directory output: xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun

    although it exited with status 0 and did produce a valid `.dmg` file.
    I suppose I’m missing some development tools? If so then please
    document that dependency, and if possible issue a more helpful error
    message that tells the user what they need to install.