Well I'm terribly sorry about this. It turns out that the gtkmm 2.6.9 release was a bad one and I share a lot of the blame since I didn't catch the ABI breakage in time, so what should have been a routine update turned into a bad release with a round of rebuilds. Upstream considers 2.6.9 "horribly broken" and insists that I push 2.6.10 immediately. The good news is you can remove the patch that commented out the set_description() call :-)
OK, no problem Denis. I'll do the rebuild tonight.
Fixed, but 0.8-5 breaks the upgrade path for newer releases, so I will have to push bump versions there.
Bumped releases for FE5 and 6, so the upgrade path is fixed again.