In 7fa2f2a62f04f095e1e27ad55aa22a8f59b1df8f, I replaced all uses of NO_WERROR
with MK_WERROR in the src repo, but this file is also used by ports where
this .error is causing problems.
I'm not sure how many ports use NO_WERROR, so this might be needed if applying
something like https://reviews.freebsd.org/rP561055 to all problematic ports
is not feasible
Reported By: tijl