VBoxManage guestcontrol hangs on execute

[Branan]

Example session:

VBoxManage --nologo guestcontrol 'Uru Build Server' execute --image 'C:\windows\notepad.exe' \
 --username buildbot --password password --wait-stdout --verbose
Waiting for guest to start process ...
Process 'C:\windows\notepad.exe' (PID: 2104) started
Waiting for process to exit ...
^C^C^C

Once I close notepad (or the process terminates on its own), VBoxManage does not end, instead it just hangs at "Waiting for process to exit ...". SIGINT has no effect on VBoxManage at this point.

If I kill the VBoxManage process and try to run a new instance of it, it will hang at "Waiting for guest to start process ..." (as if some sort of lock was never released by the killed process?). No process is ever launched in the VM. As far as I can tell, this can't be fixed without restarting the VM.

The VM is pretty lightweight - currently the only program installed is Visual Studio.

[Branan]

VBox.log