Multiple local distfile directories?

[Michael Huff <mphuff%gmail.com@localhost>]

Hi

I'm wondering if there's a way to tell pkgsrc to search multiple *local* 
distfile folders, so I can re-use what I've already downloaded without 
having everything splatted in a single folder? For example, I have:

/usr/pkgsrc-2018Q3/distfiles

/usr/pkgsrc-2018Q4/distfiles

/usr/pkgsrc-2019Q1/distfiles

I would like to set it up so that when I build a package, pkgsrc 
searches in those directories for the source and only downloads it from 
the net if the file isn't found in one of them. I've read the guide, the 
faq and the closest I can find to what I'm looking for is 
pkgtools/dfdisk, but according to the DESC file it only works with 
cdroms and network locations.


Thanks for your help!