Testing for VBoxManage startvm exit status fails

[KwadroNaut]

When building a vbox image, VBoxManage always returns 1 instead of zero.

veewee vbox build jessie -n --force --debug
…
Error: We executed a shell command and the exit status was not 0
2015-11-19 12:32:20 +0100 - ui - [veewee] - Command :VBoxManage startvm --type headless "jessie".

• Command :VBoxManage startvm --type headless "jessie".
  2015-11-19 12:32:20 +0100 - ui - [veewee] - Exitcode :1.
• Exitcode :1.
  2015-11-19 12:32:20 +0100 - ui - [veewee] - Output :
  Waiting for VM "jessie" to power on...
  VM "jessie" has been successfully started.
• Output :
  Waiting for VM "jessie" to power on...
  VM "jessie" has been successfully started.
  2015-11-19 12:32:20 +0100 - ui - [veewee] Wrong exit code for command VBoxManage startvm --type headless "jessie"
  Wrong exit code for command VBoxManage startvm --type headless "jessie"

See:
kwadronaut@hazelaar:/dev/veewee$ VBoxManage startvm --type headless "jessie"
Waiting for VM "jessie" to power on...
VM "jessie" has been successfully started.
kwadronaut@hazelaar:/dev/veewee$ echo $?
1

vboxmanage --version
5.0.10r104061

I have built vboximages last week, is this a regression in virtualbox or where should I start looking?