[chemax]

export PATH=$PATH:/opt/vc/bin/
Where did you put this?

This may solve the path issue for your user, but not for kodi,
it depends on how kodi is launched, if it's systemd unit it probably won't help as is.
I'm not familiar with xbian.

I've already asked you for a debug log.
Depending on what's on the log I may provide a 100% working workaround.

i put this to .bashrc xbian and root...
Thank you, asavah, you are my hero. Last build worked fine!
and sorry, I missed your ask for a debug log. and I dont know where it is %)