When I run
> spiceinit from=some.cub web=true
I get a segmentation fault which provides zero useful error information. I have confirmed that at least a few other folks besides me are also getting this behavior. I happen to be using ISIS 5, but I suspect that it is more about the web portion than spiceinit, since I also happen to have the relevant SPICE kernels locally, and running the above command without
web=true results in success.