Python 3.4 Travis fail due to unmet dependencies

[orbeckst]

The Python 3.4 tests are all failing now:

UnsatisfiableError: The following specifications were found to be in conflict:
  - numpy=1.15 -> *[track_features=blas_openblas]
  - numpy=1.15 -> python[version='>=3.7,<3.8.0a0'] -> tk[version='>=8.6.7,<8.7.0a0']
  - python=3.4
Use "conda info <package>" to see the dependencies for each package.

Examples:

• https://travis-ci.com/MDAnalysis/mdanalysis/jobs/144464939
• https://travis-ci.org/MDAnalysis/mdanalysis/jobs/425782569

Do we need to pin numpy or should we deactivate 3.4 tests?

cc: @richardjgowers @jbarnoud @tylerjereddy

[zemanj]

We could pin the numpy version here as yet another band-aid. Though, what we really want is something like "take the highest possible version that is compatible with this python version". Is there a sane way to achieve this without doing nasty things like parsing the output of conda info?

[richardjgowers]

I thought figuring this stuff out was something conda was meant to figure out for itself. Maybe we're not giving conda enough information initially to make these decisions. Pinning on the 3.4 build is an easy fix which wil allow PRs to continue though

[orbeckst]

We will have to do something soon because this holds up merging of all PRs.

I thought figuring this stuff out was something conda was meant to figure out for itself. Maybe we're not giving conda enough information initially to make these decisions.

Yes, I though so, too. Perhaps this is actually a bug in one of the build recipes (maybe @kain88-de sees immediately what's wrong) or in the ci-helper script (???) but that doesn't help us right now.

What is the last version of numpy that works for us in 3.4? We then pin that version, using ci-helper's NUMPY_VERSION

PYTHON_VERSION=3.4 NUMPY_VERSION=1.14 CODECOV="true" SETUP_CMD="${PYTEST_FLAGS} --cov=MDAnalysis" 

(or whatever is needed)

[kain88-de]

This looks like a conda error. Numpy 1.15 has not been build for python3.4. This is coming up now because the 1.15 version has been published 6 days ago.

Ci-helpers uses a default pin of 1.15 for numpy as the latest stable version. This pin causes a problem for python3.4 so using a different pinned version is a good solution.

[orbeckst]

Should we open an issue with ci-helpers?

[kain88-de]

I wouldn’t we use the right solution and it will be harder for them to support numpy stable based on python version. We could nicely ask conda forge to build the new numpy for python 3.4. There might be other dependencies that break later though.

…

On Mon 10. Sep 2018 at 18:48, Oliver Beckstein ***@***.***> wrote: Should we open an issue with ci-helpers? — You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHub <#2066 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AEGnVnRdD75gCpMQzgzB6KiozU67RaR9ks5uZpfjgaJpZM4WgDSO> .