Comment (by Samuel Cupp):

Is the thorn not publicly available? There’s no way to include a thorn that isn’t public as far as I’m aware. A public repo needs to be set up asap in order for it to be able to be checked out by the toolkit. I didn’t realize this was all still private.

--
Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2747/inclusion-of-sgrid-importer-in-einstein