Richard Braun:
Note that installing a mail transfer agent on an isolated system
actually makes sense. It's one way between local users to communicate,
and it's used by apt to notify you about some important changes when
you install/upgrade packages. Besides, it's a pure Debian thing,
unrelated to the Hurd.
It doesn't make sense on a system where I am the sole local user and I
can see the installation notices on the screen right in front of me when
I am doing such upgrades. It's related to the Hurd inasmuch as the
Debian installer *makes it impossible for us users to install Debian
Hurd*. That approach to this is backwards. Considering exim to be
mandatory, even on a system with no networking, one user, and no need
whatsoever for anything other than some C++ development tools, results
in the installer failing when it tries to configure exim and Debian Hurd
to be uninstallable by design. Whereas considering exim to be optional
(which seems very likely given that there's a checkbox in the Debian
installer where "mail" can be deselected) means that this is, rather, an
installer problem (of some sort: I'm not ruling out the possibility that
it was secretly doing something else when it said that it was
configuring exim on the screen.) to be corrected.