jahshaka-2.0-rc1 expects to find libmlt.so-0.2.1 and not version 0.2.2, and it segfaults soon after launch if the file is absent. This is quite annoying because I think I ended up with mlt-0.2.2 in the course of rebuilding things to get jahshaka working in the first place. A symlink from the 0.2.1 version to the 0.2.2 version seems to have worked, insofar as jahshaka has at least launched successfully.
Removing from tree, see bug 150116