[Aptitude-devel] Bug#867635: Bug#867635: mention --target-release will not work on packages already installed

[積丹尼 Dan Jacobson]

OK then at the bottom of

       -t <release>, --target-release <release>
           Set the release from which packages should be installed. For
           instance, "aptitude -t experimental ..."  will install packages
           from the experimental distribution unless you specify otherwise.

           This will affect the default candidate version of packages
           according to the rules described in apt_preferences(5).

           This corresponds to the configuration item APT::Default-Release.

please add

           Thus -t will only upgrade. To downgrade, append '=version' to
           each package.

else there is little chance the user will master the apt_preferences man
page well enough to understand that.

DK> You have to apply extra force if you really want that (pkg/release),
DK> but note that downgrading packages isn't
DK> officially supported by Debian so you might end up with a broken system
DK> if you downgrade the wrong package.

OK, perhaps also mention how make -t work for downgrades too...

E.g., The user would like to downgrade package A along with its dependencies.