Comment (by Roland Haas):

I have the dependency, that does unfortuantely not fix it:

REQUIRES CarpetX Loop 

It would not affect what include files I see though, since Cactus has no notion of any thorn "owning" an include file declared in interface.ccl since they all actually just append to the include file, ie multiple thorns can have INCLUDE HEADER: foo.hxx IN foo.hpp.

I think this is just an oversight since all other users of reduction.hxx (well io_norms.cxx) include loop.hxx first, before including reduction.hxx and they do have a global dim in their namespace (from CarpetX I guess.

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Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2933/carpetxs-reductionhxx-is-not-self