Activation environment(s)?

[Vladimir Kudrya]

Hello.

In context of a modern systemd-managed user session, is there a separate 
dbus activation environment, or is it merged with systemd? If one 
intends to manage environment variables, is systemctl (or 
org.freedesktop.systemd1.Manager Environment) enough?

A variable added by dbus-update-activation-environment (even without 
--systemd option) shows up in systemd activation environment. I couldn't 
find a pure dbus service to check if reverse is true.