@geever, you were right, I was missing the devscipts.
Unfortunately simply using a slightly older datapackage doesn't seem to work, so im compiling it now completely.
@ nixiepixel First, you should only use one source, then make sure that it is aktive (there is a nice gui in system-> software-sources.)
If you can't get the source to work, for some reason, you could open the repo's directory in a browser and load the packages manually.