There is a bit of misunderstanding here. Lines in /etc/apt/sources.list
(as well as in sources.list.d) are just a description of used
repositories. By itself they couldn't change anything in the OS. When
you 'apt-get update' it downloads package lists. This is fine, as no
damage was done yet. But when you use apt-get upgrade, or apt-get
install (something), then those new package lists may mess up system.
The reason is that some packages may have other packages as
dependencies, and those dependencies from the newer debian version may
conflict with existing ones, or cause some packages removal (f.e. some
package may say that it 'replaces' some other package).
Rolling back this testing/stable mix is a huge pain. If you done some
minor installation of something without dependencies, than you may just
revert it back to older version. It there was a major update, then...
Well, upgrade to testing and live with it. Or reinstall OS.
If you want to understand the state of your system, look here:
/var/log/apt/history.log - log of installations/upgrades
/var/log/apt/term.log - output of installation process
You can see currently installed packages: dpkg -l
For each package you can see 'policy' by using apt-cache policy command.
It shows which version of a given package is coming from which release.
F.e.: apt-cache policy xpad
The main pain point here is dependencies of dependencies... I was able
few times roll back back upgrade, but it took me few hours of heavy
work, and I couldn't recommend doing this to anyone.
TL;DR;
1. If you just added those lines in sources.list - just remove them
2. If you added them and used apt-get update - remove them and call
apt-get update again
3. If you installed or upgraded your system after that - you have a problem
On 12/06/18 22:15, murta...@stat.orst.edu wrote:
I mistakenly added two lines with 'testing' to my 'sources.list' file,
which now looks like this:
deb http://debian.osuosl.org/debian/ stretch main non-free contrib
deb-src http://debian.osuosl.org/debian/ stretch main non-free contrib
deb http://security.debian.org/debian-security stretch/updates
main contrib non-free
deb-src http://security.debian.org/debian-security stretch/updates
main contrib non-free
deb http://debian.osuosl.org/debian/ stretch-updates main contrib
non-free
deb-src http://debian.osuosl.org/debian/ stretch-updates main
contrib non-free
# my bad:
deb http://ftp.us.debian.org/debian/ testing main non-free contrib
deb-src http://ftp.us.debian.org/debian/ testing main non-free contrib
I have read that it's difficult or impossible to revert to 'stable'
once 'testing' packages have been installed. I have also read that
it's not a good idea to have both 'stable' and 'testing' repositories
in 'sources.list', so I'm wondering how to proceed. I experimented
with replacing 'stretch' by 'buster' in the first six lines above (and
removing the last two lines), but then the system couldn't find the
stable google-chrome repository in '/etc/apt/sources.list.d'. I now
have the uncomfortable feeling that I'm playing with fire.
Thanks in advance for any suggestions about if/how I should edit my
'sources.list' file!
-Paul
