Ok, I checked the wall. The report windows states I need to do 10 damage but doesn't show how many damage I'm doing. (I think that boosted barbarian is able to do more than 10 damage but let's assume it is not a bug). I cracked the wall with a bomb – 36 damage and went in.
The problem is – now I can't leave the same way I just went in. So… yeah. An interesting turn of events. ;p
