I've just spent the afternoon getting the IDE building on an installation of OpenBSD4.8 (freshly updated to -stable). But when I launch the IDE, all I get is a message dialog saying "Invalid Memory Access".
I had to tweak the uppsrc/Makefile to account for many of my headers and libraries being under /usr/local/include, /usr/local/lib. Only some of the libs & headers on my system are under /usr/include & /usr/lib that the makefile assumes everything is under. These folder choices were made by the default behavior of the OpenBSD package system.