Upon further inspection, this wasn't caused by the softlink... the hacked version of dmsetup in the qole.org repo did not use the udev rules but simply ignored that part of the original package. Now, I fixed the failure and you DO get the udev rule as per the original package (can't be a bad thing, right ?). Yell if this is not what you wanted.

PS. As it's about 2:40 AM here and my eyes are closing, I first uploaded the package to the Fremantle queue by mistake. The fun part is that it actually went through the autobuilder without a hitch, so... we have devmapper in Fremantle

EDIT: If you don't know how to solve the postrm/exec format problem, just do a
and all will be well