Comment (by Roland Haas):

There was some discussion on this in the Einstein Toolkit call just now. The situation seems that one can enable Tmunu storage but disable Tmunu being actually set by setting TmunuBase::stress_energy_storage = yes and TmunuBase::stress_energy_at_RHS = no . TmunuBase relies on running in MoL_PostStep. Since Tmunu is a derived quantity like the primitives it may be most consistent with other codes to have Tmunu set at INITIAL at the same time say HydroBase_Con2PrimInitial is running by scheduling the SetTmunu group in there instead of only in MoL_PostStep. This would rely on checking on ADMSbase_SetADMVars and possible touch HydroBase as well in case setting Tmunu uses primitive variables.

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Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2497/illinoisgrmhd-is-incompatible-with-setting