SHELL

add-apt-repository 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