Error: 'multiverse' invalid + Error: 'universe' invalid
I apparently solved it by doing this:
RUN sed -i "/^# deb.*multiverse/ s/^# //" /etc/apt/sources.list
RUN sed -i "/^# deb.*universe/ s/^# //" /etc/apt/sources.list
Instead of this:
RUN add-apt-repository multiverse
RUN add-apt-repository universe
Thank you very much Alexander Mills, I had the same problem and I was able to solve it on my system (Q4OS 3.10.3) with:
sudo sed -i "/^# deb.*multiverse/ s/^# //" /etc/apt/sources.list
sudo sed -i "/^# deb.*universe/ s/^# //" /etc/apt/sources.list