O problema está resolvido!
Eu resolvi isso com remove libpq5 :
sudo apt-get remove libpq5
sudo apt-get install libpq-dev
Eu não consigo instalar o libpq-dev para o postgresql, eu tentei
sudo apt-get install libpq-dev
e saída
Building dependency tree
Reading state information... Done
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:
The following packages have unmet dependencies:
libpq-dev : Depends: libpq5 (= 9.3.9-0ubuntu0.14.04) but 9.4.4-1.pgdg14.04+1 is to be installed
E: Unable to correct problems, you have held broken packages.
como corrigir esse problema?
O problema está resolvido!
Eu resolvi isso com remove libpq5 :
sudo apt-get remove libpq5
sudo apt-get install libpq-dev