Hm, so conda exists on ppc64le but scripts need to be tweaked to use that.

And there is no conda for s390x/arm64, as if we need a new "ports-arch" python tests.

Thanks, interesting, I wasn't aware Travis supported those!

Not sure about running them at each build, but we could certainly run them in a cron job (or at least some of these arch) cc @glemaitre

And there is no conda for s390x/arm64, as if we need a new "ports-arch" python tests.

Hmm, if we have to build scipy/numpy from sources that will be slow..

@rth, @glemaitre, @thomasjpfan sorry for jumping in...
wasn't planned to no longer use Travis?
See #15185 and #15189 .

wasn't planned to no longer use Travis?

We were because we no longer needed it (aside for the cron job maybe). But at the same time some time ago, we were considering how to run CI on ARM. #13073 proposed using another CI service (Shippable), but if we can do that in Travis we might as well just keep it since we already have the setup.

There does not seem to be an arm64 build of conda, as used by travis setup scripts.
I'm not sure if you have some other ways to deploy the required deps on arm64. Maybe just use the available xenial/bionic packages?

numpy scipy are available pre-built, but not sure about version numbers though.

numpy scipy are available pre-built, but not sure about version numbers though.

We still use Travis as a CRON job to install nightly built. I think it could be worth to add the new platform until we are able to use wheels for these platforms or that we are not having a timeout.
A daily CRON job for these platforms would be enough.

I think that on these systems we should the packaging system as much as we can and pip otherwise. This would go faster.

I experimented with travis ci with arm using the packaging system by the OS and I have been hitting the 50 minute timeout limit. The build takes around 20 minutes, and the tests can take more than 30 minutes long.

Reference: https://travis-ci.org/thomasjpfan/scikit-learn/jobs/614672030

The only way is to have 2 CRON jobs. One to build and cache the install and one to run the tests.

@rth, @ogrisel, @thomasjpfan, after #17996 is this PR still relevant? Thanks!

Let's close this but if someone wants to build on top of #17996 to add build config to test on ppc64le (POWER8/9), feel free to do so. Miniforge should be able to provide the scikit-learn build and test dependencies for that platform:

https://github.com/conda-forge/miniforge/#download