v1.2.0

Fixed reboots hanging when rebooting Unix VMs.
You must use the provided packer binary.

Usage example:

    {
      "type": "shell",
      "inline": [
        "echo BEFORE REBOOT CODE",
        "echo unix-reboot; sudo reboot; sleep 60"
      ]
    },
    {
      "type": "shell",
      "inline": [ "sleep 60" ]
    },
    {
      "type": "shell",
      "inline": [
        "echo POST REBOOT CODE"
      ]
    }

v1.1.0

• pre_boot_host_scripts (array of strings) - List of scripts to execute on the
  XenServer host prior to booting the VM. The VM's UUID will be passed into each
  script as the first parameter. The script can be of any type: bash, python, ruby, etc.
  Each script must start with a shebang, ie. #!/usr/bin/env bash.
• pre_export_host_scripts (array of strings) - List of scripts to execute on the
  XenServer host prior to exporting the VM. The VM's UUID will be passed into each
  script as the first parameter. The script can be of any type: bash, python, ruby, etc.
  Each script must start with a shebang, ie. #!/usr/bin/env bash.
• remote_ssh_port (integer) - SSH port of XenServer host. Only useful when using
  pre_boot_host_scripts or pre_export_host_scripts. Default is 22.

v1.0.0

You probably don't need the packer binary, but it's what I used to test the two builders, so here it is in case it doesn't work with your version of Packer.