Ok, I've messed around a bit, and I just can't figure out how to get qt-funk's build command to actually place source code into the tarball; it apparently has to run in the "build" directory, and only object files exist there. I'm pretty sure the Extras system wants the actual source code, right? It looks like I'll have to do something quite different to create a source package...

Update: Ok, blew away my build directory and started completely fresh build. Now, the tarball just has a .deb file inside it, none of the object files from before. I still don't understand fully what is going on here, but I'm guessing I just needed to clean things up from my previous failed attempts.

Anyway, I'll push this into Extras-devel, and start on the next level of error messages.