Problem linking against pthread in 15.11

Hey Genodians,

I just updated to 15.11 (building on linux_x86) whenever a component links against pthread, I am getting an error such as

Program app/qt5/examples/calculatorform/calculatorform LINK calculatorform build/var/libcache/pthread/pthread.lib.so: undefined reference to `_context_area_start'

(This one comes from qt, but of course make run/pthread comes up with something similar) Build directory was cleaned beforehand. Has anyone faced such an issue before or did something go wrong during my update?

Best Marcus