> a) pkgs that install, and should[1] install in /usr/X11R6

Hm  You seem to be missing a footnote [1]

What packages "should" install in the projectroot and why ?
Always wondered, would be interested to know the rationale..

> B is somewhat more "elegant" to the user, but really a bear for the developer.

probably easier to move /usr/X11R6 somewhere where configure won't find
it while building the packages in that case :-)  Hmm or
just mount something on top of it (ugh).

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