DEBCONF_FRONTEND and DEBIAN_FRONTEND
I am somewhat puzzled about the relationship between the two
env variables DEBCONF_FRONTEND and DEBIAN_FRONTEND.
The usersguide from the debconf docs says:
you can set the DEBCONF_FRONTEND environment variable to the name of the
frontend to use. For example:
On the other side /usr/lib/perl5/Debian/DebConf/Config.pm uses
the variable DEBIAN_FRONTEND:
If DEBIAN_FRONTEND is set in the environment, it overrides all this.
Are these actually the same variables (and there is a typo in the docs?)
If not, what is the difference?