Package: freeciv Version: 2.6.0-4 Freeciv doc/README.packaging about the new gtk3.22-client: "This client suits better for systems with gtk+-3.22 than the gtk3-client compatible with much older gtk+ versions."
(Since that text has been written, gtk+ project changed their decision that 3.22 would be the last version of gtk+-3. Above should say that "...systems with gtk+-3.22 or gtk+-3.24...") - ML