Reading package lists... Done
Building dependency tree
Reading state information... Done
You might want to run 'apt --fix-broken install' to correct these.
The following packages have unmet dependencies:
 mysql-cluster-community-server : Depends: mysql-common (>= 7.6.3-1debian7)
                                  Depends: mysql-client (= 7.6.3-1debian7)
 mysql-server : Depends: mysql-server-5.6 but it is not going to be installed
E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).