A. Pagaltzis wrote:
* Matt Brown <matt(a)mattb.net.nz> [2005-09-27 12:35]:
In technical terms they are marked to remove because the maintainers of the Exim or Postfix packages have specified that the conflict with each other and should never be installed at the same time.
That’s the obvious explanation for `postfix` and `postfix-tls`.
But what about `mutt` and `mailx`?
mutt depends "exim4 | mail-transport-agent", so postfix, sendmail or exim etc will satisfy it as postfix provides mail-transport-agent. Depending on the package manager you use, to install exim4, the first thing you must do is remove postfix. At the time it is removed, you no longer have either exim4 or mail-transport-agent installed, so it queues mutt and mailx for removal. When you install exim4 later in the same opreation, the dependencies are again met and I assume the programs stay installed.
And once those are explained, how does it manage to conclude that `ubuntu-base`, `anacron`, `at` and `lsb` have to be uninstalled?
ubuntu-base is a metapackage that depends on all the packages that a standard Ubuntu install comes with. This means you can type 'apt-get install ubuntu-base' and get the ubuntu base system, which includes postfix. If you remove any of the base components, the dependencies for ubuntu-base are no longer on the system, so it removes the package - it doesn't actually -do- anything. I run Ubuntu with Exim on dozens of machines and have no problems whatsoever. Craig