Masking system libraries

["Sijmen J. Mulder" <ik%sjmulder.nl@localhost>]

Hi,

Buildlink exposes /lib, /usr/lib and such because those aren't thought
to pollute the build environment.

This is true on BSD and macOS but not on most Linux distributions where
that distinction isn't as clear. I found some of my own packages didn't
build on a fresh Debian install that didn't include packages like
ncurses or zlib.

Wouldn't it be better to mask the system directories as well and only
link builtins are that are explicitly depended upon? I'm not sure how
we'd deal with headers, perhaps masking just the lib/ directories would
be a better start. Or perhaps I'm completely misguided.

Sijmen