enable installing with PROJ 6.0.0

[snowman2]

Addresses #1288

[snowman2]

Looks like it will actually install now. The test still fail, but I am not sure how you want to handle those.

[snowman2]

CLA signed.

[QuLogic]

It looks like this might need a bit more work to get tests to pass with proj6?

[snowman2]

Correct, but the scope of this PR is simply to enable installing with PROJ >= 6.0.0.

The test results are different than previous versions due to updates in PROJ that I believe are more correct. The main question is: does cartopy want to have different expected test results based on the version? Or just to update the tests to the new version?

[dopplershift]

😱

[whyboris]

Could we release this? I'm unable to install cartopy because

#error 'To use the proj_api.h you must define the macro ACCEPT_USE_OF_DEPRECATED_PROJ_API_H'

This happens while installing pyviz 😅

[dopplershift]

I don't have the cycles to push out a release right now, but I will be trying to get CartoPy to a next release at the SciPy sprints next month. Help getting PRs reviewed and finished welcome.

[djhoese]

I know @dopplershift said he'll be working on this at SciPy, but has anyone else put more work in to this? I have a tutorial at SciPy that would benefit from having the CRS objects from pyproj 2.0+ but as far as I know that requires PROJ 6.0+ and my tutorial uses cartopy.

@snowman2 @dopplershift What's left to do on this? Can I help? Or is most of the trouble in the time to create a release?

[snowman2]

@djhoese if this is not released by the time your tutorial happens, you could install the dependencies of cartopy with proj 6+ and do:

pip install git+https://github.com/snowman2/cartopy.git@5e624fe

[ocefpaf]

@djhoese and @snowman2 that can be hard for the attendants due to the c extensions in cartopy. Maybe we can publish the "dev" release on a conda-forge dev label. Would that help?

[djhoese]

I suppose if it is easy enough to install, but attendees have already starting installing stuff by following my instructions so maybe it is better to just wait for a full release? I can live with the older versions of pyproj and just explain what's "coming down the pipeline" if I have to.

[dopplershift]

@djhoese If it were my tutorial, I'd feel better about living with current releases, unless they're hopelessly broken. Can never be sure when volunteer-run projects will actually have enough the time to do a release.

[djhoese]

😉 @dopplershift Tell me about it. No problem. Thanks for all your work and status updates.

[dopplershift]

Let's at least get this in so we can build against current things. We'll work on fixing the tests next.

[hnsywangxin]

you can try add ADD_DEFINITIONS(-DACCEPT_USE_OF_DEPRECATED_PROJ_API_H=1) cmakelist.txt

[dopplershift]

@hnsywangxin We don't use cmake to build, so I'm not sure how this is relevant? Also, this PR has already been merged, so I'm not sure that's adding anything.

[2sn]

CFLAGS="-DACCEPT_USE_OF_DEPRECATED_PROJ_API_H" pip3 install cartopy

[snowman2]

@2sn, these are open source projects. As such, you are welcome to contribute to improve them. That being said, pyproj 3.0.1 should work with PROJ 8. See: https://pyproj4.github.io/pyproj/stable/installation.html

[snowman2]

Changes needed to be compatible in #1140

[2sn]

@snowman2 Found workaround, see above. May not be new. Installing on older OS, not all libraries may be up to date.
but, as I said, even installing from github

pip install git+https://github.com/snowman2/cartopy.git

does not fix the problems w/o the environment setting.

Thanks for your work on the project. Seems monumental task.