Attempted to install the stable version of the Opera browser a few minutes ago. Opera requires the libatk-bridge2.0-0 package, but I already have libgtk-3-0t64 and libatk-bridge2.0-0t64 packages installed, which are required for other apps that I have installed; e.g. audacious, pcmanfm. So I get the following error when I attempt to install the libatk-bridge2.0-0 package:
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
Unsatisfied dependencies:
libgtk-3-0t64 : Depends: libatk-bridge2.0-0t64 (>= 2.15.1) but it is not going to be installed
Recommends: libgtk-3-bin
Error: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.