coastlines not downloadable for cartopy via julia conda.jl

[ggebbie]

PyCall can be installed with a julia-specific version of python, but the coastlines dataset can no longer be accessed via the NaturalScience website pointed at in cartopy 0.18. See also SciTools/cartopy#1849.

[ggebbie]

One fix is to update the julia-specific version of python from within Julia:
ENV["PYTHON"] = ""
Pkg.build("PyCall")
restart REPL?
Conda.add("matplotlib",channel="conda-forge")
Conda.add("shapely",channel="conda-forge")
Conda.add("cartopy=0.20.0",channel="conda-forge")

The shapely library may not need updating. I tried updating it to fix a SSL_Certificate unverified error. This error appears on a laptop, but not on a desktop. It could be checked by repeating the same process in python.

If cartopy doesn't download the coastline files, they can be copied from an outside version of python, but the location has changed from cartopy 0.18.0 to 0.20.0. Now they reside in .local/cartopy/....

[ggebbie]

See https://github.com/JuliaLang/NetworkOptions.jl#verify_host for info on SSL_CERTIFICATE not verified problem.