A new version of GRASS GIS got released, which gave me an opportunity
to bump the version in the old definition and recompile. The errors are
there, but do not hinder the successful build. Apparently, they have
been there from the beginning; I just didn’t notice — both bad and
good news.

The real error (for now) is

   In unknown file:
            0 (%resolve-variable (7 . wxpython) #<directory (g…>)

   ERROR: In procedure %resolve-variable:
   Unbound variable: wxpython

I tried changing “wxpython” to “python-wxpython”, but this also
is not recognized. So there’s something wrong with the way I defined
the wrapping.

WŻ