diskimage-builder/diskimage_builder/elements/debian-minimal/pkg-map

{
  "release": {
    "debian": {
      "testing": {
        "systemd": "systemd",
        "systemd-sysv": "systemd-sysv"
       }
     }
   },
  "default": {
    "systemd": "",
    "systemd-sysv": ""
  }
}