cross-port ${filespath} access?

[René J.V. Bertin]

Hi,

A bit of an unorthodox thought:

There are ports that expose different elements built from a single source archive, typically installed through a main port on which those ports depend. The typical approach would see those ports created as subports of said main port, but that can lead to an overly complex portfile. Thus, the different flavours of the mysql and postgresql Qt4 plugins are provided through separate "metaports" instead of through port:qt4-mac .
It would be nice if one could bundle all patches required for that single source archive with the main port, rather than distribute (or even copy) them over/among the various other ports that build from that same source archive.
It's possible to set dist_subdir so that one can at least avoid to download and store the archive multiple times; is there an equivalent to set ${filespath} to `port dir ${mainport}`/files ?

Thanks,
R.