Numpy 2.0 Compatibility

[jbpezent]

The recently released numpy 2.0 appears to be incompatible with latest basemap version 1.4.1. Seems to be a common issue with packages compiled against older versions of numpy. Issue observed on windows 11 with python 3.9 when importing basemap.

[DWesl]

As I recall, the fix for this would be adding metadata to the effect of requires: numpy<2.0 to existing binary wheels and (re-)compiling new binary wheels with numpy>=2.0,<3.

In the meantime, installing basemap from source with pip install --force-reinstall --no-binary :all: basemap should work until basemap does a new release with new binaries (1.4.1post1 might be fastest, but the maintainers might be close enough to 1.4.2 to wait for that). (EDIT: This will compile NumPy and Matplotlib from source, so it will likely take half an hour to an hour)

[valeriupredoi]

@DWesl I can just go open a PR at feedstock with the new pin, and create a new build, in the meantime, if you OK with that? If basemap does indeed support numpy>=2.0.0 at upstream (here), that is 🍺

[cvanelteren]

Was able to make it work with

git clone --depth 1 https://github.com/matplotlib/basemap.git
cd basemap/packages/basemap
pip install --force-reinstall --no-binary :all: basemap

Thanks!

[DWesl]

@DWesl I can just go open a PR at feedstock with the new pin, and create a new build, in the meantime, if you OK with that? If basemap does indeed support numpy>=2.0.0 at upstream (here), that is 🍺

My platform only has up to Python 3.9, so I'm not able to check anything with NumPy 2.0 until someone works out how to compile Python 3.12 there and packages it.

[molinav]

My main concern while I keep the pin numpy<2.0 for now is that NumPy 2.0 brings some API breaking changes that have been waiting around for some years. Since basemap was started very long ago, I would not be surprised that basemap has some old ways of doing things (e.g. using NumPy members that were removed or moved somewhere else).

Because of that, I would like to invest a bit of time reviewing the source code before pushing a new release with potential bugs (note that the test collection is quite limited). Unfortunately, I have been a bit busy in the last months, but I have not still forgotten the latest open issues and PR.