Instalei o zentyal em um dos meus servidores de teste, mas tive alguns problemas com ele e optei por removê-lo. Eu removi o repositório de pacotes da lista de fontes e usei apt-get remove zentyal e apt-get purge zentyal e apt-get autoclean && apt-get clean cache Mas agora não consigo instalar nenhum pacote porque ele reclama de dependências com pacotes sendo substituídos por zentyal, por exemplo
The following packages have unmet dependencies:
bind9 : Depends: libbind9-90 (= 1:9.9.5.dfsg-3ubuntu0.5) but 2:9.9.5.dfsg-3+zentyal is to be installed
Depends: libdns100 (= 1:9.9.5.dfsg-3ubuntu0.5) but 2:9.9.5.dfsg-3+zentyal is to be installed
Depends: libisc95 (= 1:9.9.5.dfsg-3ubuntu0.5) but 2:9.9.5.dfsg-3+zentyal is to be installed
Depends: libisccc90 (= 1:9.9.5.dfsg-3ubuntu0.5) but 2:9.9.5.dfsg-3+zentyal is to be installed
Depends: libisccfg90 (= 1:9.9.5.dfsg-3ubuntu0.5) but 2:9.9.5.dfsg-3+zentyal is to be installed
Depends: liblwres90 (= 1:9.9.5.dfsg-3ubuntu0.5) but 2:9.9.5.dfsg-3+zentyal is to be installed
E: Unable to correct problems, you have held broken packages.
No seu caso, você precisa fazer o downgrade de cada pacote
sudo apt-get update
sudo apt-get install libbind9-90=1:9.9.5.dfsg-3ubuntu0.5 libdns100=1:9.9.5.dfsg-3ubuntu0.5 libisc95=1:9.9.5.dfsg-3ubuntu0.5 libisccc90=1:9.9.5.dfsg-3ubuntu0.5 libisccfg90=1:9.9.5.dfsg-3ubuntu0.5 liblwres90