DO NOT MERGE: Remove libgdal matrix, update to gdal 3.1 (take 2)

[xylar]

Checklist

• [x] Used a personal fork of the feedstock to propose changes
• [x] Bumped the build number (if the version is unchanged)
• [ ] Reset the build number to 0 (if the version changed)
• [x] Re-rendered with the latest conda-smithy (Use the phrase code>@<space/conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• [x] Ensured the license file is being packaged.

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

[xylar]

@conda-forge-admin, please rerender

[xylar]

Based on this comment from the developer: https://rasterio.groups.io/g/main/message/600, it seems like rasterio 1.1.5 will work with libgdal 3.1 and proj 7.1.0

I wasn't able to re-open #171 because the branch had been deleted so I'm opening a new PR.

[xylar]

@akrherz, many tests are failing with GDAL 3.1.2. If you want to dig into this and try to figure out why, that would be great. I don't really have time.

[akrherz]

Thank you @xylar ! I am reviewing this all now.

[akrherz]

It appears to me the test failures are just with test_transform_bounds_densify, which would likely be a proj issue? I see the tests ran against 7.1.0, I wonder if it is fixed in 7.1.1 ? This mapbox/rasterio#1987 PR appears to be passing checks with the GDAL 3.1 and Proj 7.1.1 combination?

[xylar]

We could test against proj 7.1.1 but until conda-forge updates to its pins to that version, it won't help because no other packages would be built with that version.

[xylar]

Yeah, we can't even test with proj 7.1.1 yet because libgdal and possibly other dependencies haven't been built with that version.

[xylar]

We would need to do a test build of all of the dependencies that need proj first with proj 7.1.1 and then do a test build of this package with those dependencies. That's a lot more work than I'm willing to put in just to find out if this package might work later on when proj migrates to 7.1.1. For now, I think I (once agian) have to conclude that this version of rasterio is not compatible with the current pins and this should be closed.

But I'll leave it open until I get your agreement, @akrherz

[akrherz]

That's reasonable, you have already gone way above and beyond here. Thanks again.

[xylar]

$ conda create -y -n test python=3.8 rasterio conda-tree
$  conda activate test
$ conda tree whoneeds proj
['geotiff', 'libspatialite', 'libgdal']

So you would need to do local builds of those three and rasterio itself with proj 7.1.1 if you wanted to see if this will work out. I can advise on how to do that but it's a lot of work.

[ocefpaf]

I started a migration to the new proj 7.1.1. I would love to move to a x.x or even x pinning in proj but their history of breaking things is in micro releases is not encouraging.

[xylar]

I started a migration to the new proj 7.1.1.

Oh, that's great!

I would love to move to a x.x or even x pinning in proj but their history of breaking things is in micro releases is not encouraging.

Yeah, there's a tricky balance to be had between making things easier for us and breaking things. In the end, it seems like stricter pins are often worth the pain. It's such a mess to clean things up if the pin is too loose.