I’ve just started using VirtualBox. I quickly ran into a problem though. I quickly found that scim prevents VirtualBox from registering the “Host Key” (the right control key by default) which is used to prompt VirtualBox to stop grabbing the keyboard input. I’ve googled for solutions but all of them were either ineffective or unacceptable. Some people suggest to exit scim before starting VirtualBox!!
I’ve found a better solution: start VirtualBox with the environment variables which control input methods cleared out:
$ unset QT_IM_MODULE
$ unset XMODIFIERS
$ unset GTK_IM_MODULE
$ virtualbox [...]
Executing the above prevents VirtualBox from communicating with scim or any other IM. How to convert this to a script is left as an exercise for the reader. It is probably not necessary to clear out all three variables but I’m not going to investigate which exactly VirtualBox uses.