Upgrading to 20.04 from 19.10 - Err:2 http://apt.postgresql.org/pub/repos/apt eoan-pgdg

Question

I am on Ubuntu 19.10 and trying to upgrade it to 20.04.1 LTS. But I get the error below when I run sudo apt update:

Hit:1 https://dl.yarnpkg.com/debian stable InRelease
Hit:2 http://apt.postgresql.org/pub/repos/apt eoan-pgdg InRelease                                           
Err:2 http://apt.postgresql.org/pub/repos/apt eoan-pgdg InRelease             
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7FCC7D46ACCC4CF8
Ign:3 https://download.rethinkdb.com/apt eoan InRelease 
Err:4 https://download.rethinkdb.com/apt eoan Release   
  404  Not Found [IP: 167.172.11.96 443]
Reading package lists... Done
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://apt.postgresql.org/pub/repos/apt eoan-pgdg InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7FCC7D46ACCC4CF8
E: The repository 'https://download.rethinkdb.com/apt eoan Release' no longer has a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

Any ideas how I can remove these errors?

I don't have postresql installed before and not sure why it shows up in the error.

Answer 1

It seems like someone setup the PGDG repository, but didn't install PostgreSQL. So the cure is simple: delete the repository configuration.

If the repository was set up following the instructions from the PostgreSQL site, the cure should be as simple as removing /etc/apt/sources.list.d/pgdg.list.