I commented out the building of pltek and found the same problem when building the examples so as you said it was nothing to do with pltek, but a fundamental build issue. The fix you suggested worked. I missed that flag when looking at the wiki, I tried every other cairo flag on there!
On the linux build section of the wiki I've added a troubleshooting section and added this to it. Maybe this would be a useful place to document little things like this as and when people come across them.