Rosegarden is uninstallable, at least on my Sid system. I get the
following error message when running apt-get install rosegarden:
The following packages have unmet dependencies.
rosegarden: Depends: kdebase-bin but it is not going to be installed
E: Broken packages
I tried and failed to reproduce this so I suspect it was just a
transiant issue (transiant uninstallability is normal in sid, it is only
if it goes on for some time that it is worth a bug report).
If you can still reproduce it could you try adding the packages it says
won't be installed to the install command line
until you get a more usefull error message out of apt?