I wanted to disable the always-visible dock that comes with the Ubuntu 17.10 version of gnome shell. I found tips to either install the dash-to-dock extensions or to just uninstall the Ubuntu dock extension. The first resulted in two overlapping docks, the latter in removing several other packages. The Ubuntu shell theme is broken now and the dock is still always visible and stuck in a broken theme.
Obviously, messing with the default extensions without fully installing vanilla gnome was a bad idea. Do you know how to undo the changes? I already re-installed the ubuntu-desktop package but that didn't fix anything so it wasn't the only one removed along with gnome-shell-extension-ubuntu-dock.
Thanks a lot.
/var/log/apt/*, and you can reconstruct the install/reinstall/whatever path you took to get to your current situation. Trace this path in reverse.