Comment (by Roland Haas):

Please do not use this tutorial. As the warning at the top of it says this tutorial has not (and will not be) updated for the "Proca" (2019_03) release of the Einstein Toolkit and the instructions provided here will fail if using ET_2019_03 instead of ET_2018_09. Please use either the online tutorial or the offline version of the tutorial notebook which will be kept up to date.

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