Tout comme toi je suis sous Sid.
Titounehome/zwz# apt-get -d install libgnomeprint6
Reading Package Lists... Done
Building Dependency Tree... Done
Package libgnomeprint6 has no available version, but exists in the database.
This typically means that the package was mentioned in a dependency and
never uploaded, has been obsoleted or is not available with the contents
of sources.list
However the following packages replace it:
libgnomeprint-data libgnomeprint-bin
E: Package libgnomeprint6 has no installation candidate