14

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?

einpoklum
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4 Answers4

20

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/gcc-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/gcc-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.

einpoklum
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2

Switch back to a supported config. They are listed in the getting started document for any recent CUDA distribution.

For your particular configuration you have currently listed, you might have better luck with CUDA 7 RC, which is now available to registered developers.

Robert Crovella
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    I can't remove gcc 4.9 from my system, or downgrade the distro for something as minor as this... – einpoklum Jan 18 '15 at 16:08
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    I switched to 7 which is really working well and it has support for 4.9. Though you might need to update to ubuntu 14.10. Also it has c++11 which is great. – flip Jan 19 '15 at 15:22
1

Very often you will find that CUDA has had newer releases by the time you encounter this problem. For example, the original formulation of the question was about CUDA 6 and GCC 4.9; CUDA 7 supported GCC 4.9. CUDA 8 supports GCC 5.x . And so on.

einpoklum
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1

I had a similar issue with CUDA Toolkit 7.5 and gcc 5.2.1.

I did modify the host_config.h file in /usr/local/cuda/include/:

Just remove the lines where it check the gcc version. It did solve my problem.

Credits goes to Darren Garvey (https://groups.google.com/forum/#!topic/torch7/WaNmWZqMnzw)

Mateusz Piotrowski
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Conchylicultor
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  • There weren't any side affects that you saw from doing this, were there? – Jacob Holloway Apr 14 '16 at 18:14
  • I didn't notice anything. Everything seems working fine – Conchylicultor Apr 14 '16 at 23:50
  • @Conchylicultor: There are multiple known incompatibilities between CUDA 7.x and GCC 5.x . It would be unwise to remove the version check. – einpoklum Dec 04 '16 at 23:13
  • @einpoklum Probably, I suppose they put this limit for a reason but this hack worked perfectly for me. Just out of curiosity, what are the incompatibilities for instance ? – Conchylicultor Dec 05 '16 at 01:01
  • Mysterious compilation failures with certain standard library constructs; weird linking trouble which I forget the details of since I didn't file a bug about them. – einpoklum Jan 06 '17 at 18:10