Comment 16 for bug 162984

The error message says that an error occured while trying to overwrite »/usr/share/themes/nimbus/metacity-1/button-close-icon-prelight.png«, which is part of package gtk2-engines-nimbus, and therefore the dpkg-deb process paste was killed with signal broken pipe.

If you add

Conflicts: gtk2-engines-nimbus

to the control file, gtk2-engines-nimbus will be removed from aptitude before installation of your package is possible, so the error would not occur (at least I think that will happen, have not tried :-) )

The other question is wether your package name (nimbus) or gtk2-engines-nimbus follows the standards for package names of desktop themes - a question I have no answer for. However, looking into the repository, other Gnome themes are also following this package name scheme: gtk(2)-engines-xxxx

http://packages.ubuntu.com/search?keywords=engines&searchon=names&suite=intrepid&section=all