ux.open_grid() crashes on files supported by Grid.from_file()

[Sevans711]

Version

v2026.09.0

How did you install UXarray?

Source

What happened?

Trying to open a .shp grid file using uxarray.open_grid() fails unexpectedly, with an error stack like:

OSError: [Errno -51] NetCDF: Unknown file format: '~/Code/uxarray/test/meshfiles/shp/cb_2018_us_nation_20m/cb_2018_us_nation_20m.shp' raised from ValueError: did not find a match in any of xarray's currently installed IO backends ['netcdf4', 'scipy'].

Using Grid.from_file() successfully opens the file and returns a Grid object. (I'm a bit suspicious that Grid.from_file() might separately have bug(s) in it, because the resulting object has n_face=82 and n_max_face_nodes = 2999, and plotting it doesn't give results which look like the US…)

What did you expect to happen?

I expected uxarray.open_grid() to default to Grid.from_file() when it gets passed a shapefile or any other file which wouldn't otherwise be supported by is actually supported by Grid.from_file(). That would be the ideal solution. Though, it would also be acceptable to just improve the error message and uxarray.open_grid docstring to clarify, if there's some reason that dispatching to Grid.from_file() automatically it not desirable.

Related: #808

Can you provide a MCVE to repoduce the bug?

import uxarray as ux
import os
UXDIR = ...   # path to uxarray on your machine
GRIFILE = os.path.join(UXDIR, 'test/meshfiles/shp/cb_2018_us_nation_20m/cb_2018_us_nation_20m.shp')
ux.open_grid(GRIDFILE)  # crashes

# this does not crash though:
ux.Grid.from_file(GRIDFILE)