Non-Python dependency problem when adding coastlines

[robertjwilson]

Pure pypi installations of nctoolkit now seem to be crashing when plotting data with coastlines. This seems to be down to a hard to identify problem with non-Python dependencies. Adding coastlines on my local machine with hvplot's coastline example crashes:

import xarray as xr
import hvplot.xarray
import cartopy.crs as ccrs

rasm = xr.tutorial.open_dataset('rasm').load()
rasm.hvplot.quadmesh(
    'xc', 'yc', crs=ccrs.PlateCarree(), projection=ccrs.PlateCarree(),
    ylim=(0, 90), cmap='viridis', project=True, geo=True,
    rasterize=True, coastline=True, frame_width=800, dynamic=False,
)

This is fine when installing from conda. So there must be a mismatch between system packages and a recent version of an nctoolkit dependency. Github Actions tests are now failing for the same reason.

For now plotting should probably have a coastline argument option and the default should be no coastline.