C++ 17 does not work on binder

[saraedum]

I am trying to prepare a few examples on mybinder.org that use C++ 17 features. However, xeus-cling does not work for me when selecting the C++ 17 kernel on binder. Since everything works fine locally, I am not sure how to debug here.

As an example, go to the following link:

https://mybinder.org/v2/gh/flatsurf/e-antic/9cde33bfff8f24cee0c9c529ed3f8551d31eb815

With the preselected C++14 kernel everything works fine. However, changing the kernel to C++17 the interface is stuck at "Connecting to kernel":

Can I somehow debug why xeus-cling seems to be unhappy?

[dokempf]

Actually, this is not Binder-related. I observe the same behaviour locally for a freshly created Conda environment (but also only for the C++17 kernel). Here is my package list:

# Name Version Build Channel _libgcc_mutex 0.1 conda_forge conda-forge _openmp_mutex 4.5 1_gnu conda-forge argon2-cffi 20.1.0 py38h497a2fe_2 conda-forge async_generator 1.10 py_0 conda-forge attrs 21.2.0 pyhd8ed1ab_0 conda-forge backcall 0.2.0 pyh9f0ad1d_0 conda-forge backports 1.0 py_2 conda-forge backports.functools_lru_cache 1.6.4 pyhd8ed1ab_0 conda-forge binutils_impl_linux-64 2.35.1 h27ae35d_9 binutils_linux-64 2.35.1 h454624a_30 bleach 4.1.0 pyhd8ed1ab_0 conda-forge ca-certificates 2021.5.30 ha878542_0 conda-forge cffi 1.14.6 py38ha65f79e_0 conda-forge clang_variant 1.0 cling_v0.8 conda-forge clangdev 5.0.0 h43905f9_1012 conda-forge cling 0.8 hf817b99_0 conda-forge cppzmq 4.7.1 hf7cf922_2 conda-forge debugpy 1.4.1 py38h709712a_0 conda-forge decorator 5.0.9 pyhd8ed1ab_0 conda-forge defusedxml 0.7.1 pyhd8ed1ab_0 conda-forge entrypoints 0.3 pyhd8ed1ab_1003 conda-forge gcc_impl_linux-64 9.3.0 h6df7d76_17 gcc_linux-64 9.3.0 h1ee779e_30 gxx_impl_linux-64 9.3.0 hbdd7822_17 gxx_linux-64 9.3.0 h7e70986_30 importlib-metadata 4.8.1 py38h578d9bd_0 conda-forge ipykernel 6.3.1 py38he5a9106_0 conda-forge ipython 7.27.0 py38he5a9106_0 conda-forge ipython_genutils 0.2.0 py_1 conda-forge jedi 0.18.0 py38h578d9bd_2 conda-forge jinja2 3.0.1 pyhd8ed1ab_0 conda-forge jsonschema 3.2.0 pyhd8ed1ab_3 conda-forge jupyter_client 7.0.2 pyhd8ed1ab_0 conda-forge jupyter_core 4.7.1 py38h578d9bd_0 conda-forge jupyterlab_pygments 0.1.2 pyh9f0ad1d_0 conda-forge kernel-headers_linux-64 2.6.32 he073ed8_14 conda-forge ld_impl_linux-64 2.35.1 h7274673_9 libffi 3.3 h58526e2_2 conda-forge libgcc-devel_linux-64 9.3.0 hb95220a_17 libgcc-ng 11.1.0 hc902ee8_8 conda-forge libgomp 11.1.0 hc902ee8_8 conda-forge libsodium 1.0.18 h36c2ea0_1 conda-forge libstdcxx-devel_linux-64 9.3.0 hf0c5c8d_17 libstdcxx-ng 11.1.0 h56837e0_8 conda-forge libuuid 2.32.1 h7f98852_1000 conda-forge markupsafe 2.0.1 py38h497a2fe_0 conda-forge matplotlib-inline 0.1.3 pyhd8ed1ab_0 conda-forge mistune 0.8.4 py38h497a2fe_1004 conda-forge nbclient 0.5.4 pyhd8ed1ab_0 conda-forge nbconvert 6.1.0 py38h578d9bd_0 conda-forge nbformat 5.1.3 pyhd8ed1ab_0 conda-forge ncurses 6.2 h58526e2_4 conda-forge nest-asyncio 1.5.1 pyhd8ed1ab_0 conda-forge nlohmann_json 3.9.1 h9c3ff4c_1 conda-forge notebook 6.4.3 pyha770c72_0 conda-forge openssl 1.1.1l h7f98852_0 conda-forge packaging 21.0 pyhd8ed1ab_0 conda-forge pandoc 2.14.2 h7f98852_0 conda-forge pandocfilters 1.4.2 py_1 conda-forge parso 0.8.2 pyhd8ed1ab_0 conda-forge pexpect 4.8.0 pyh9f0ad1d_2 conda-forge pickleshare 0.7.5 py_1003 conda-forge pip 21.2.4 pyhd8ed1ab_0 conda-forge prometheus_client 0.11.0 pyhd8ed1ab_0 conda-forge prompt-toolkit 3.0.20 pyha770c72_0 conda-forge ptyprocess 0.7.0 pyhd3deb0d_0 conda-forge pugixml 1.11.4 h9c3ff4c_0 conda-forge pycparser 2.20 pyh9f0ad1d_2 conda-forge pygments 2.10.0 pyhd8ed1ab_0 conda-forge pyparsing 2.4.7 pyh9f0ad1d_0 conda-forge pyrsistent 0.17.3 py38h497a2fe_2 conda-forge python 3.8.10 h49503c6_1_cpython conda-forge python-dateutil 2.8.2 pyhd8ed1ab_0 conda-forge python_abi 3.8 2_cp38 conda-forge pyzmq 22.2.1 py38h2035c66_0 conda-forge readline 8.1 h46c0cb4_0 conda-forge send2trash 1.8.0 pyhd8ed1ab_0 conda-forge setuptools 58.0.3 py38h578d9bd_0 conda-forge six 1.16.0 pyh6c4a22f_0 conda-forge sqlite 3.36.0 h9cd32fc_0 conda-forge sysroot_linux-64 2.12 he073ed8_14 conda-forge terminado 0.12.0 py38h578d9bd_0 conda-forge testpath 0.5.0 pyhd8ed1ab_0 conda-forge tk 8.6.11 h27826a3_1 conda-forge tornado 6.1 py38h497a2fe_1 conda-forge traitlets 5.1.0 pyhd8ed1ab_0 conda-forge wcwidth 0.2.5 pyh9f0ad1d_2 conda-forge webencodings 0.5.1 py_1 conda-forge wheel 0.37.0 pyhd8ed1ab_1 conda-forge xeus 1.0.4 h7d0c39e_0 conda-forge xeus-cling 0.12.1 h560cc44_0 conda-forge xtl 0.7.2 h4bd325d_1 conda-forge xz 5.2.5 h516909a_1 conda-forge zeromq 4.3.4 h9c3ff4c_1 conda-forge zipp 3.5.0 pyhd8ed1ab_0 conda-forge zlib 1.2.11 h516909a_1010 conda-forge

[nthiery]

I encountered the same problem, though with some variations. Whether the kernel crashes
seems to depend not only on the conda environment but on the underlying OS/hardware???.
We have some computers in our computer lab where this happens, others not. All under
Linux Mint; can't recall from the top of my head whether it's the same version though.
I also get glibc incompatibilities issues.

I can try to dig and record more detailed information; all this happened in lab sessions, so
with little time to take notes :-)

[SylvainCorlay]

I am working on release a new stack based on cling 0.9 which may improve the situation.

(Unfortunately, that involves providing new variants of llvm and clang on conda-forge, hence the delay).

[EmmanuelDgz]

Facing same issue on a clean installation.

[srpgilles]

In fact, this seems to be not limited to the C++ 17 kernel. I tried using notebooks I did years ago on Binder and none of the C++ kernels seems so start properly; I have then tried the Binder link provided here in the README here... and got exactly the same result.

It might be related to the underlying hardware as @nthiery pointed out, but in this case I was really unlucky because I had the issue both with GESIS and OVH.

[nthiery]

For the record: I managed to get C++17 to work (but not C++11 or C++14) consistently
by forcing gcc=9.4.0. Presumably it was not OS related after all, but just some other
discrepancy in the student setup.

Looking forward the new release! Thanks @SylvainCorlay

[srpgilles]

Thanks @nthiery, you're right by forcing the gcc version it seems to work just fine.

[YarelisAcevedo]

@nthiery How do I force the gcc version?

[srpgilles]

@YarelisAcevedo In your environment.yml file.

[YarelisAcevedo]

Thanks! @srpgilles