Travis CI OS X Platform support/OS X Compatibility

Travis CI has switched from OS X 10.9 with XCode 6.1 to 10.11 with XCode 7.3 as their default OS for Mac. It appears this was announced on their blog and was switched out yesterday. However, we weren’t aware of this change and so have not done anything about this until now. As a consequence, there is ~1days worth of packages that may not be compatible with 10.9 (more investigation will be required) and need to be rebuilt to restore that compatibility.

To switch back to the previously used base image, fixes have been put in play in staged-recipes with PR ( https://github.com/conda-forge/staged-recipes/pull/1717 ) and conda-smithy with PR ( https://github.com/conda-forge/conda-smithy/pull/325 ) releases as part of v1.3.2. Feedstocks created by staged-recipes from this point forward should be on the supported platform 10.9. Any feedstock that has not been re-rendered should be re-rendered with 1.3.2 before doing any build number bumps or new releases (though this can be part of the same PR).

It appears that Travis CI plans on dropping 10.9 at the end of the month. So the oldest OS we can work with will be 10.10. If we wish to still support 10.9, we should do one or more of the following.

1. Raise an issue upstream with Travis CI requesting the image remain.
2. Scope out other CIs that will meet or allow us to meet this requirement.
3. Try to install the 10.9 SDK in the VMs ourselves and build against it.
   • https://github.com/devernay/xcodelegacy
   • https://github.com/phracker/MacOSX-SDKs
4. Bump our OS X requirements to 10.10.

If you know of options meeting these or some other option, please raise them. Please share your thoughts. Will be raising this in our next meeting.

Thanks to @dopplershift who raised a lot of this information to our attention in PR ( https://github.com/conda-forge/staged-recipes/pull/1716 ).

Edit (pulled in from comment): Raised this on gitter as well.

Edit: Have raised issues or made comments on open PRs to encourage re-renderings on feedstocks that compiled code on 10.11 recently that need to be moved back to 10.9 and rebuilt.

cc @conda-forge/core

[dopplershift]

That would seem to be good news generally. I’m happy to help test, but none of the things I maintain are compiled at this point. CartoPy and netCDF4 (and assorted dependencies) are the things I personally care most about.

[jakirkham]

So I have downloaded a copy of XCode 6.4. It will only run on 10.10 so it can’t be run on 10.9. However, I went searching for the included SDKs and it does appear that the 10.9 SDK is included. Here is the path inside the Application ( Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk ). Also Travis CI confirms that the 10.9 SDK is included in the installed copy of XCode on the xcode6.4 image. This should greatly reduce the amount of work we have to go to as we can still maintain OS compatibility when switching images.

There are still a few remaining issues worth worrying about. First is bugs we encounter from switching XCode/compiler version, which would be a per feedstock problem ultimately. Though it may be worth getting some feeling on that before we start switching. Second is feedstocks that are not already setting their OS X compatibility by either using the toolchain or explicitly setting it need to address this.

cc @conda-forge/core