Re: Problem dependencies
On Thu, Oct 30, 2025 at 8:05 PM William Torrez Corea
<willitc9888@gmail.com> wrote:
> I have problem dependencies with my DEBIAN 12.
> I tried to install DEBIAN 13, cancel the download, try to return to DEBIAN 12 and the system crashed.
Downgrades are NOT supported.
Nevertheless, sometimes folks are able to successfully do so,
or do so with certain packages or combinations thereof.
If you have full backups, you may want to just restore from that,
as it may be both faster and more practical.
If you followed the recommended upgrade steps, including at least
the suggested particularly relevant files and configuration data,
e.g. contents under /etc, that may be helpful.
You can also examine the /var/log/dpkg.log* files,
to determine what package changes were made (or perhaps even attempted),
and in what order, and work to essentially reverse that, by reversing the order.
dpkg has a --force-downgrade option, use with caution.
dpkg has options --no-act, --dry-run, --simulate,
you may want to use those before doing any actual dpkg changes
without such options, to preview and get at least some idea
of the likelihood of them possibly actually working.
See also dpkg(1) and dpkg --help-force
You can also use apt-get with the -d option to download package(s).
Can be quite handy to do that before attempting installs/downgrades,
notably in case you do something that breaks apt and/or networking
or download capabilities. Similarly, if one doesn't have them
installed and available, would be prudent to have the ar,
curl, and wget programs installed.
See also:
https://wiki.debian.org/CrossGrading#Suggested:_have_ar.2C_curl.2C_and_wget
as downgrading has many of the same risks and perils as CrossGrading,
and probably even more so.
Likewise, the cautionary note towards the start (currently 2nd paragraph) of
https://wiki.debian.org/CrossGrading
is also quite applicable. But if your system is already quite broken,
perhaps you don't have as much to potentially lose in attempting.
The -t option to apt (and apt-get) may also come in quite handy
to specify the target release, e.g. to explicitly select bookworm.
Good luck!
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