I have Ubuntu 16.04.4 LTS. I've tried to run
and suddenly have found that it wants to install apache2-bin among other new packages in order to upgrade to 18.04. I can't understand why it's needed.
My machine doesn't have apache installed but
/etc/apache2 directory exists and contains the only file
I don't know how it could appeared, maybe I installed apache previously and removed it later, but Synaptic shows apache2-* package as not installed (without any remaining conf files).
UPDATE: After running rdepends as suggested in comments I've found that gnome-user-share suggests apache2-bin, also it suggests libapache2-mod-dnssd which is also listed for install by the release upgrader.