Comment (by Jonah Miller):

Ah. Indeed, I’m using a mac. OSX 10.14.6 mojave. And I’m using the system svn out of /usr/bin/svn. Presumably the correct fix is indeed to install it via a real package manager.

I think that message is good. It’s clear enough to a mac user with a package manager what to do in that case, I think.

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Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2293/thornlists-entry-for-external-libraries-on