h5netcdf not tested in nightly run

[kmuehlbauer]

What is your issue?

I've just found that h5netcdf is commented out for the nightly runs (unix):

xarray/pixi.toml

Lines 191 to 194 in cf19e74

	flox = "*"
	# h5netcdf = "*"
	# h5py = "*"
	opt_einsum = "*"

This was there right from creation of pixi.toml. I currently do not remember the reason for that. Should this be enabled again?

(cc) @VeckoTheGecko

[keewis]

for the reasoning for that see #10888 (comment) and the following comments.

As a summary:

• h5netcdf depends on h5py, which depends on numpy
• we absolutely want to have a upstream-dev version of numpy
• conda-forge's h5py pulls in a released version of numpy, which can't be overridden by a PyPI dependency (pixi first solves the conda deps, then the PyPI deps)
• scientific-python's version of h5py is incompatible with netcdf4 (conflicting versions of libhdf5)

This conflict is what made us skip h5netcdf in the nightly CI, and we'll have to resolve it before we can add h5netcdf back.

[kmuehlbauer]

Thanks a bunch @keewis!