Using Python 3.7.0 for 2018b toolchains might be a problem

[akesandgren]

There are some packages that are still not Python 3.7 compatible which may be a reason to downgrade the 2018b toolchains Python to the latest 3.6.x.

Problem codes detected so far:

• TensorFlow
• protobuf-python

[boegel]

I think @mboisson also had some other problematic Python packages with Python 3.7, which doesn't seem to be fully backwards compatible with earlier Python 3.x versions, see also the problems I ran into with pandas: pandas-dev/pandas#21785

Should we revisit the Python 3.x versions we picked for 2018b and go forward with 3.6.6 rather than 3.7.0 now we still can?

cc @easybuilders/easybuild-easyconfigs-maintainers

[mboisson]

Yes. I have recompiled our wheels for Python 3.7 around mid-July. Here are the ones that did not recompile correctly for one reason or another :

• cutadapt
• fuel
• HTSeq
• mdtraj
• msgpack_python
• msmbuilder
• openslide_python
• pysam
• python_Levenshtein
• python_lzo
• PyWavelets
• ray
• velocyto

[boegel]

First step: easyconfigs for Python 3.6.6 with foss/2018b & intel/2018b in #6703

Next step: move all *-Python-3.7.0 easyconfigs using foss/2018b or intel/2018b currently merged in develop to -Python-3.6.6 instead.

That's still feasible, since none of those are included in master or the latest EasyBuild release.

Not sure if we should also remove Python-3.7.0-foss-2018b.eb & Python-3.7.0-intel-2018b.eb...
The test we have to check for dependency variants should ensure that we don't accept PRs that use Python 3.7.0 rather than 3.6.6 in easyconfigs using a 2018b toolchain?

[akesandgren]

If 3.6.6 is decided on, instead of 3.7.0, I can change my PR's to start with (and I +1 on dropping all 3.7's)

[boegel]

#6703 is merged, switch to Python 3.6.6 for 2018b toolchain generation is done in #6710

[boegel]

Both #6703 and #6710 have been merged, so closing this too...