Another problem - the launchpad builder was putting the entire cantarell source at /src/usr/share/fonts/cantarell/, not just the four font files. I adjusted this so only the ttf folder from the source is put in.
Another problem - the launchpad builder was putting the entire cantarell source at /src/usr/ share/fonts/ cantarell/ , not just the four font files. I adjusted this so only the ttf folder from the source is put in.