Comment (by Roland Haas):

Hello Jason,

it seems your are using the “master” version of at least the EOS_Omni thorn. This version cannot be mixed with “realease” versions of Cactus / Carpet right now. You will have to use either “master” for everything or a release version for everything. Using all master the code compiles fine for me.

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Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2371/compile-error-in-ubuntu