hello i was trying to migrate all my project to unity and i had this problem, when i use ./Unity the prompt output is the next
./Unity: error while loading shared libraries: libpq.so.5: cannot open shared object file: No such file or directory
I’m not sure which distro you’re on, but I’m pretty sure that belongs to PostgreSQL.
my distro 4.2.0-27-generic #32~14.04.1-Ubuntu SMP Fri Jan 22 15:32:26 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
I don’t use Ubuntu so this may be wrong, but this should install it for you 
sudo apt install postgresql
@NathanWarden_1 Hey I had the same problem and that fixed it. Thank you