Comment # 13 on bug 99078 from Furkan

Does your problem disappear when you downgrade your LLVM packages to 3.9 from
here:
https://launchpad.net/~oibaf/+archive/ubuntu/graphics-drivers/+sourcepub/6850286/+listing-archive-extra

If you run dpkg -l | grep 3.9.1, I think that should get you the list of
packages that you'll need to download from that page.