gcc ABI incompatibility

[c0g]

setup.py assumes tensorflow was compiled by gcc 4.x. My tensorflow is compiled with 5.x, so the line:

    if gcc_version == 5:
        compile_command += " -D_GLIBCXX_USE_CXX11_ABI=0"

causes an undefined symbol error. Removing it makes everything work. I'm not sure if there's a way to work out which ABI tensorflow was compiled with.

Probably not going to get many people, but might worth making a note in the readme or something.

[icouckuy]

I think everyone will have this issue if they download the pip package of tf0.11. I have a PR on this but it hasnt been merged it

[markvdw]

Is this the PR you're talking about? #222

I think this is definitely an important issue. It looks like the current state of affairs is:

• The TensorFlow official binaries are compiled with gcc4, the code checks for gcc5 (or higher with Minor fix for gcc 6 #222) and adds the appropriate flag if necessary.
• If TensorFlow is compiled with gcc5, the extra flag is not needed, but it is currently added, because we assume the official binaries are used.

@icouckuy I've recently installed GPflow with tf0.11 without your pull request on my mac. So I didn't see the issue you predicted. Why did you expect this?

Technically, the GPflow policy is to only support one version of TensorFlow, and only the official binaries. And that's currently supported (possibly with the addition of #222). However, it's probably best to automatically check what version of GCC TensorFlow was compiled with. From this stackexchange post, we can find the GCC version of a binary using (e.g.):
strings -a ~/anaconda3/lib/python3.5/site-packages/tensorflow/contrib/rnn/python/ops/_lstm_ops.so | grep "GCC: ("

Does anyone know where the TensorFlow binaries are stored? I found the .sos by searching, but it only turned up contributed ops, which I don't really want to rely on.

[icouckuy]

Sorry, I was talking about the official binaries which is different from cog's problem. I 'm assuming most people would install the official TF binaries on a recent (i.e., gcc6) linux distribution. At least everyone in our group had the same problem of undefined symbols (fixed with #222).

[alexggmatthews]

We no longer have user ops.