Solved by tom in post #2 
              
              
                I’ve been one of the people who used GCC 5 for a long time. 
With recent cuda (I’m currently on 9.2) supporting newer GCC I had switched to 6 and this week (because I had trouble with MKLDNN’s use  of -werror) to gcc 7. 
For my (CPU only) laptop, I always use the default compiler of Debian/unstable,…