The question is about a specific combination of versions but is relevant more generally.
I've just dist-upgraded from Kubuntu 12.04 to 14.04. Now, when I want to compile CUDA code (with CUDA 6.5), I get:
#error -- unsupported GNU version! gcc 4.9 and up are not supported!
I installed gcc-4.8 (and 4.7), and tried to use the symlinks-in-/usr/local/cuda/bin solution suggested here:
CUDA incompatible with my gcc version
but this doesn't work. What should I do?
This solution is relevant to multiple combinations of CUDA and GCC versions.
You can tell CUDA's nvcc to use a specific version of gcc. So, suppose you want gcc 4.7 for use with CUDA 6. You run:
sudo apt-get install gcc-4.7 g++-4.7
and then add the following switch to your nvcc command-line:
nvcc --compiler-bindir /usr/bin/g++-4.7 # rest of the command line here
If you're building with CMake, add an appropriate setting before looking for CUDA to your CMakeLists.txt, e.g.:
set(CUDA_HOST_COMPILER /usr/bin/g++-4.7) # -> ADD THIS LINE <-
find_package(CUDA)
Also, it seems clang can compile CUDA as well, maybe that's worth experimenting with (although you would have to build it appropriately).
Note: Some Linux (or other OS) distributions don't have packages for multiple versions of gcc (in the same release of the OS distribution). I would advise against trying to install a package from another release of the distribution on an older release, and consider building gcc instead. That's not entirely trivial but it is quite doable - and of course, it's your only option if you don't have root access to your machine.