Couldn't find foreign struct converter for 'cairo.Context'

TypeError: Couldn't find foreign struct converter for 'cairo.Context'

This error was caused by one of the application installed in the OS. It's easy to fix it - try to install packages it needs:

sudo apt-get install python3-gi-cairo

or

sudo apt-get install python-gobject-cairo

https://github.com/rbgirshick/py-faster-rcnn/issues/221