Today I was trying to complete Thoughtbot’s Upcase Fundamental of TDD Exercise and ran into an issue after I cloned the repo. I tried to run the command bin/setup but it was not completed because the logs said I needed to use ruby 2.6. So I thought no problem, I’ll used rvm - a ruby version manager. I ran the command rvm install 2.6 but got an error because one of my ppa repository was returning a 404 error. Specifically

Err:8 jolnir Release
  404  Not Found [IP: 443]

This was an annoying issue to troubleshoot because I use elementary os, a ubuntu based distro, which has its own distro name ie jolnir. Because elementary, does not have native docker support it was added to the repo list manually. The repo list are /etc/apt/sources.list and /etc/apt/sources.list.d/docker.list. In the latter list, the distro was listed as jolnir and not focal. I decided to view both list with nano a terminal editor per this post. After a quick edit to correctly reference focal, and rerunning the commands to install ruby 2.6, bin/setup was able to be completed as intended.

Now to finish up this exercise!