Hackage vs. uscan (debian/watch) in darcs.d.o repos

[twb@cybersource.com.au (Trent W. Buck)]

Two styles of hackage watchfiles can be found on darcs.debian.org:

  http://hackage.haskell.org/packages/archive/hashed-storage/([\d.]+)/hashed-storage-([\d.]+).tar.gz

and

  opts="uversionmangle=s/\.(\d)(?=\.|$)/0$1/g;s/\.(\d\d)(?=\.|$)/$1/g" \
  http://hackage.haskell.org/cgi-bin/hackage-scripts/package/HTTP /packages/archive/HTTP/.*/HTTP-([\d\.]*)\.tar\.gz

Both styles can only "see" the latest tarball, and thus "uscan
--download-current-version" cannot be used to get a tarball after a
"darcs get".  It's useful to do so in order to produce .changes and .dsc
files for feeding into debdiff (to compare with one's new version).

Could this be addressed by a simple patch to hackage?

PS: I have a feeling this has already been discussed, but I can't find
the thread in the list's archive.