Gnome control center crashes

[Volker Wysk]

Am Freitag, den 04.10.2019, 06:22 +0200 schrieb Ralf Mardorf via
ubuntu-users:
> On Fri, 04 Oct 2019 00:32:17 +0200, Volker Wysk wrote:
> > But it should be possible to revert to the official version, which
> > is
> > in the standard repositories, isn't it? The version which got
> > replaced
> > by the one from that PPA.
> 
> Hi,
> 
> the command recommended by Colin is seemingly doing this, see
> http://manpages.ubuntu.com/manpages/bionic/man1/ppa-purge.1.html .
> 
> It is replacing packages from the PPA with packages from official
> repositories, if those packages are provided by official
> repositories.
> 
> If you replace a core component such as libglib2.0-0 from the PPA
> with
> the package from official repositories, resolving dependencies could
> become tricky. I could imagine possible dependency cycles, OTOH I
> don't
> know how exactly apt works.
> 
> Probably the script (or apt) tries to resolve dependency cycles, but
> might fail to do so in some cases. I don't know. I could imagine that
> it does replace a lot of packages, but it might not always be
> possible
> to resolve everything in by the first step, so additional steps might
> be to run "apt install --fix-broken" and/or "dpkg --configure -a".
> 
> Keep in mind that some packages provided by a PPA might either be
> provided by another package name, than provided by the official
> repositories or it might not be provided at all by official
> repositories. IOW it depends on the content of the PPA if everything
> can be fixed automatically. In the end it should be possible to fix
> the
> install in a way, that it becomes an official Ubuntu install, but
> perhaps is missing packages provided by a PPA, that aren't available
> by
> official repositories.
> 
> _Warning!_ Some software configurations and/or data might not be
> backwards compatible. After running upgraded software it could
> migrate
> configurations and/or data from an old, to a new format, but
> downgraded
> software can't convert configs and/or data from a new to an old
> format.
> 
> I suspect that you won't suffer from a new vs old data/configure
> format
> issue in $HOME, but you might lose some individual configurations by
> purging packages in /etc/, so you might need to backup those configs
> and to restore them. Since I never used ppa-purge and I never have
> taken a look at the script, it's all guessing.


Thanks for your elaborate explanation! It turned out I didn't need it.
See my other message.

Cheers,
Volker