I recently had to go through a full, clean install for PDL on cygwin
and ran into a couple of issues relating to getting PGPLOT up:
(1) Had to build the patched pgplot which I needed to hand
edit to add PNG support to the build
(2) Then I needed to use the patched PGPLOT-2.19-CD.tar.gz
rather than the stock PGPLOT release.
I would like to see the patches to the pgplot library
updated so these fixes aren't required and for the
modifications needed for rgbi support folded into
the main PGPLOT module tree (in such a way that
it would work with or without the patched pgplot
At that point, it should be possible to implement
an Alien::PGPLOT module to take care of the
patching and building.