translate URLs into something in PS files that is recognized by LaTeX as a hyperref
From a sprawling discussion on the forum:
LaTeX proves that it is possible to include hyperlinks in PostScript. They are disregarded by PS viewers, but ps2pdf makes use of them & produces a PDF with active hyperlinks. I don’t know how it works, but I believe GV could produce PostScript that’s enhanced in that way. This would ultimately enable LaTeX docs to have interactive graphs that are GV-generated. It’s potentially a trivial fix, but OTOH the document could not at the same time embed files using the attachfile pkg (but pdftk could be used as a hack to embed files as a separate step).