Installing Zabbix for pgsql on Ubuntu 20.04 fails

[beriapl]

I've tried to install zabbix-server-pgsql on fresh install of Ubuntu 20.04, and it fails with:

The following packages have unmet dependencies:
zabbix-server-pgsql : Depends: libevent-2.1-6 (>= 2.1.8-stable) but it is not installable
Depends: libsnmp30 (>= 5.7.3+dfsg) but it is not installable
E: Unable to correct problems, you have held broken packages.

However:

apt list --installed | grep libevent
libevent-2.1-7/focal,now 2.1.11-stable-1 amd64 [installed]

apt list --installed | grep libsnmp3
libsnmp35-dbg/focal-updates,focal-security,now 5.8+dfsg-2ubuntu2.3 amd64 [installed]
libsnmp35/focal-updates,focal-security,now 5.8+dfsg-2ubuntu2.3 amd64 [installed,automatic]

[supereric]

i had the same problem
since i was using ubuntu focal i had to update my /etc/apt/sources.list and add below lines to it

deb http://us.archive.ubuntu.com/ubuntu/ focal main universe
deb-src http://us.archive.ubuntu.com/ubuntu/ focal main universe
deb http://us.archive.ubuntu.com/ubuntu/ focal-security main universe
deb http://us.archive.ubuntu.com/ubuntu/ focal-updates main universe
deb-src http://us.archive.ubuntu.com/ubuntu/ focal-security main universe
deb-src http://us.archive.ubuntu.com/ubuntu/ focal-updates main universe

then

apt update

apt install zabbix-server-mysql zabbix-frontend-php zabbix-apache-conf zabbix-sql-scripts zabbix-agent

[tc0nn]

Just pointing out that any Amazon AWS EC2 Ubuntu instance uses the Amazon Repo's instead. supereric 's solution above fixed this for me.