Basic Question about Backports

deadface · 2018-10-27 16:47:20

Hello All

I have a basic question regarding backports. This is related to the fact that I finally am reinstalling/upgrading to Helium with an nvidia card. I do require accelerated graphics so the nouveau drivers aren't going to work.

OK. I installed Helium several times on my machine and enabled backports. My intention was to install several other small packages (remmina etc) not related to nvidia. I followed this process to get nvidia drivers installed

https://forums.bunsenlabs.org/viewtopic.php?id=3844

During the process, I did not specify to use the back repository. However, several careful attempts end with a dependency error during:

sudo apt-get install nvidia-driver

My final attempt was to start from scratch and not enable backports that are offered by bl-welcome. The nvidia installation went completely fine.

Just so that I understand, when backports are enabled do packages get automatically upgraded to the latest backport version when installed? If not, can anyone give me a hint why the dependency failure occurred during the installation of nvidia-driver?

As a follow-up, I have everything up and running. Can I temporarily enable then disable backports to get 'remmina' installed?

Thanks
deadface

nobody · 2018-10-27 17:51:45

deadface wrote:

Just so that I understand, when backports are enabled do packages get automatically upgraded to the latest backport version when installed?

No. Packages from backports (and our backports) come with a priority of 100. Regular repositories have 500. When you install a package if the package is available from repositories r1 and r2 with two different priorities p1 and p2 where p1 > p2, then the package will automatically be installed from r1 but if and only if also p1 >= 500. If a package is already installed from a repository with a priority < 500 say 100 (backports default) and new versions with higher version numbers are available from two more repositories with priorities of 100 and 500, respectively, then the next automtaically installed package version is the maximum version from all repositories with a priority of 100 and higher.

In short, if you already installed a package from backports, then APT may upgrade it to another backports version.

See https://linux.die.net/man/5/apt_preferences for more information. It's needlessly complicated but that's Debian.

If not, can anyone give me a hint why the dependency failure occurred during the installation of nvidia-driver?

The APT dependency resolver is not without … issues.

Try

apt-get -t stretch-backports dist-upgrade
# or
apt-get -t stretch-backports install ANY-PACKAGE

or post detailed error output, otherwise we don't really know anything about your specific situation. The -t specifies the 'target release' and alters the scope in which APT's dependency resolver looks for candidates. Alternatively, you can try aptitude instead of apt-get; it uses its own solver.

deadface · 2018-10-27 19:29:53

@nobody, thanks for the detailed reply and I think I understand. I have since enabled the Debian and Bunsenlabs backports and installed the other packages that I need.

I do think I should have saved the dependency error from my first two attempts but they are gone due to a re-installation.

One final follow-up. Does it make any sense to completely deactivate backports since I have no other interest in anything from that repository. By make sense, I mean would it prevent future issues.

Again, Thanks.

hhh · 2018-10-27 19:42:28

deadface wrote:

One final follow-up. Does it make any sense to completely deactivate backports since I have no other interest in anything from that repository. By make sense, I mean would it prevent future issues.

Yes, disable the repo if you don't need it. Keep it simple, silly.

johnraff · 2018-10-28 02:59:07

deadface wrote:

Does it make any sense to completely deactivate backports since I have no other interest in anything from that repository.

If you have installed backported software, then disabling the backports repository will prevent you from getting any (possibly security-related) upgrades to those packages - at least until the version in the regular repository goes higher, which won't likely happen for a long time.

#1 2018-10-27 16:47:20

Basic Question about Backports

#2 2018-10-27 17:51:45

Re: Basic Question about Backports

#3 2018-10-27 19:29:53

Re: Basic Question about Backports

#4 2018-10-27 19:42:28

Re: Basic Question about Backports

#5 2018-10-28 02:59:07

Re: Basic Question about Backports

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