8.6 Reverting a Version
Reverting an installed package to an earlier version is an ordinary downgrade, and runs through the ordinary transaction machinery with the ordinary guarantees.
8.6.1 The procedure #
- Query the archive index for the available versions of the package.
- Select the desired one.
- Run an upgrade with that version as the new version, which requires explicit downgrade authorisation (§6.5).
8.6.2 Constraints #
The target has to be available from a configured repository's archive index, or already cached locally. A version pruned from the archive cannot be reached without an externally supplied package file.
Reverting may require adjusting dependents whose constraints the older version does not satisfy. The resolver determines that, and the plan may include further downgrades or removals.
8.6.3 Scope #
Reverting a package's version reverts that package's payload and nothing
else. Registry state, configuration materialised by reconcillers,
runtime data under /var/, and user data are unaffected.