The repository 'http://ppa.launchpad.net....does not have a Release file.

15 May 2020

Ever followed a guide a little to blindly and added a repository and now expereincing issues such as:

The repository 'http://ppa.launchpad.net/{something}/archive/ubuntu focal Release' does not have a Release file.

Solution:

sudo add-apt-repository -r ppa:{reponame}
sudo apt update

For me this happened to be:

sudo add-apt-repository -r ppa:longsleep/golang-backports
sudo apt update

And you should be back in business.