I wanted to purge/reinstall the gnome-shell-extension-appindicator package, but when I did that, two other packages ubuntu-desktop and ubuntu-gnome-desktop got purged with it.
So I restarted, thinking that I probably need to reinstall those, but everything seems ok! I always thought those two are some critical packages.
Should I reinstall them?
I have 18.04 installed.
ubuntu-desktopandubuntu-gnome-desktopare metapackages. That is, they don't contain any software, but are set to depend on the packages which make up the desktop. So when you installubuntu-desktopyou will automatically get all the necessary packages, because they are dependencies. When you removed appindicator,ubuntu-desktopgot removed too because it no longer had all the necessary dependencies. – AlexP May 31 '18 at 23:28