The solution for the issue I raised is found here, https://www.reddit.com/r/Kalilinux/comments/jfitq5/openvas_install_errors/, and relates to OpenVas looking for postgresql on port 5432. Specifically,
"The problem is actually being caused by a port mapping issue. By default, Kali comes with postgres 12, but OpenVAS installs version 13. Postgres assigns a higher port (5433, in this case) for additional versions on the system. But OpenVAS is still looking for 5432.
A quick solution is to edit the "
port = " lines in the
configuration files. Give the v. 13 port the value of 5432, and give the v. 12 port any other value. Then restart postgres using:
sudo systemctl restart postgresql"