$ pkcon install gconf-editor
Resolving                     [=========================]         
Querying                      [=========================]         
Testing changes               [=========================]         
Finished                      [                         ] (0%)  
The following packages have to be installed:
 gconf-defaults-service-3.2.6-3ubuntu1.amd64	GNOME configuration database system (system defaults service)
Proceed with changes? [N/y]