backports: how to prevent incompatibilities?

HextorBRX · 2019-01-07 14:00:24

Hello

I am going to use backports for the first time and I read the official documentation: https://backports.debian.org/Instructions/#index3h2 I would like to prevent eventual incompatibilities so I have a few questions:

1) If a package is already installed on Devuan stable (e.g. LibreOffice, Firefox etc), do I have to uninstall it prior to installing the backported version? According to the documentation, backported packages are not necessarily compatible with stable libraries but they should be. I would rather not use the newest libraries, unless it is absolutely necessary.

Backports are recompiled packages from testing (mostly) and unstable (in a few cases only, e.g. security updates) in a stable environment so that they will run without new libraries (whenever it is possible) on a Debian stable distribution

2) Would you advise me to comment out/delete the following line in /etc/apt/sources.list once the backported package is installed?
deb http://ftp.debian.org/debian stretch-backports main
Is this the same line in Devuan by the way?

3) I noticed that a few Debian users update from backports with the following command:

sudo apt -t stretch-backports upgrade

https://linuxconfig.org/how-to-install- … -backports
I am not sure this is a good idea to update from backports in a stable environment. Moreover, I will not use more than one backported package.

Thank you

golinux · 2019-01-07 15:36:26

Backports can be useful to accommodate newer hardware etc. But never use Debian or other 3rd party repos like mint or ubuntu. Use the devuan backports. All this information is on devuan.org so please have a look there..

HextorBRX · 2019-01-07 20:28:01

1) no need to uninstall a package
2) indeed, everything is on devuan.org but also in /etc/apt/sources.list
3) since there is no security support for packages from backports, all I have to do is install the backported package, uncomment those lines, and update-upgrade my system as usual?

Last edited by HextorBRX (2019-01-07 21:09:53)

golinux · 2019-01-07 21:55:31

HextorBRX wrote:

1) no need to uninstall a package

I don't know if amprolla will recognize and update packages installed directly from Debian.

HextorBRX wrote:

2) indeed, everything is on devuan.org but also in /etc/apt/sources.list

Then why would you use Debian repos when it says this in several places on the website:

Devuan package repositories are exclusive. Other repositories, including Debian, Ubuntu, Mint etc, should NOT be used directly.

HextorBRX wrote:

3) since there is no security support for packages from backports, all I have to do is install the backported package, uncomment those lines, and update-upgrade my system as usual?

I'm pretty sure that the backports repo in ascii is pinned so you must use `-t ` to download and no need to comment. You'd have to ask on the debian forums whether you would have to comment those lines from their repo. Probably wouldn't hurt.

thierrybo · 2019-01-07 23:26:28

HextorBRX wrote:

3) since there is no security support for packages from backports, all I have to do is install the backported package, uncomment those lines, and update-upgrade my system as usual?

You do not have to uncomment backport repository. It is not the same as adding testing repository to your sources.list. Backports are specially crafted packages to use in your "stable" system, to fit in stable and not breaking anything.

If you install packages from backports repository (with "-t ascii-backports") and let it in your sources.list, it will NOT bring you unwanted packages. You will only get updates to those you installed (and their dependencies) from these backports. This si even adviced otherwise you won't get updates to these backports.

I use devuan stable with backports repository activated for at least one year and the only updates I get from backports were packages I installed or their dependancies

golinux · 2019-01-07 23:48:55

@thierrybo . . . He installed this package from the DEBIAN repo directly so will your solution still be valid?

HextorBRX · 2019-01-08 16:21:08

I do not use Debian repos, only their documentation. I commented the following lines in /etc/apt/sources.list

deb     http://deb.devuan.org/merged <release codename>-backports main
deb-src http://deb.devuan.org/merged <release codename>-backports main

I assumed it was advised to comment them out as soon as the backported package is installed. I must have misunderstood the instructions: "It is advised to disable backports and only enable to install specific packages." (devuan.org) https://devuan.org/os/etc/apt/sources.list

If you install packages from backports repository (with "-t ascii-backports") and let it in your sources.list, it will NOT bring you unwanted packages. You will only get updates to those you installed (and their dependencies) from these backports. This si even adviced otherwise you won't get updates to these backports.

Ok then. So you are saying I should keep the above lines commented and a regular update such as sudo aptitude update && sudo aptitude safe-upgrade will upgrade the backported package and its dependencies?

Thank you

golinux · 2019-01-08 16:49:38

Just want to make sure you understand that <release codename> will need to be replaced with jessie or ascii (without the < >).

When devuan was just starting, there was some testing of amprolla that merged the main repos with backports and I got a bit burned by that so I always comment backports even though I know it's OK to just use -t. Not a problem since I really don't need anything from there.

HextorBRX · 2019-01-08 21:33:59

Everything is in /etc/apt/sources.list, there is no margin for error. I did not have access to a computer, nor did I have to tweak sources.list in the past. You are right to clarify this but I don't do anything until I read it in the documentation and experimented in a virtual machine.

I understand that a regular update such as sudo aptitude update && sudo aptitude safe-upgrade is only going to fetch the required packages from backports but everything I read made me think I had to close the valve. The following links refer to the official documentation:

no security support: https://backports.debian.org/FAQ/

risk of incompatibilities with components from the stable version: https://backports.debian.org/Instructions/#index3h2

enable them on demand only: https://devuan.org/os/etc/apt/sources.list

Well, let's say it is highly confusing for something that is actually quite simple. It's ok to keep backports enabled if I fetch one package but upgrading everything is not recommended: sudo aptitude update && sudo aptitude -t ascii-backports upgrade
I am going to stick with sudo aptitude update && sudo aptitude safe-upgrade (backports enabled)

golinux · 2019-01-08 21:36:33

Let us know how it works out.

ChuangTzu · 2019-01-08 22:24:59

It's ok to use backports for a limited number of programs/packages, its not recommended to upgrade to everything available in backports. As pointed out make sure all of your repos only point to Devuan and not Debian.

thierrybo · 2019-01-08 22:41:00

HextorBRX wrote:

I assumed it was advised to comment them out as soon as the backported package is installed. I must have misunderstood the instructions: "It is advised to disable backports and only enable to install specific packages." (devuan.org) https://devuan.org/os/etc/apt/sources.list

Sorry but i'm afraid this was written by someone who do not understand how backport repository work in Debian. This seems to be a copy/paste advice from a sentence related to adding temporarily testing or sid repository to just install one package. However the advice to install only specific packages that you need is true. For me I need three things : a more recent virtualbox, nvidia-driver and kernel package.

HextorBRX wrote:

Ok then. So you are saying I should keep the above lines commented and a regular update such as sudo aptitude update && sudo aptitude safe-upgrade will upgrade the backported package and its dependencies?
Thank you

Yes, not commented. Every time i use sudo aptitude update && sudo aptitude full-upgrade I get stable updates and for example new virtualbox versions from backports if available.

Neither https://backports.debian.org/Instructions/ or https://wiki.debian.org/Backports advices to remove repository after installing a package, I trust more debian documentation to Devuan documentation on this topic and more than one year with this setup.

Last edited by thierrybo (2019-01-08 22:43:45)

HextorBRX · 2019-01-09 16:34:59

It worked like a charm

Yes, not commented.

To put it plainly, I mean backports enabled in /etc/apt/sources.list

What you say makes sense and it is confirmed in this guide, that you should be able to understand because your nickname gives it away https://linux.developpez.com/tutoriels/ … eme#L8-2-3

Edit

Every time i use sudo aptitude update && sudo aptitude full-upgrade I get stable updates and for example new virtualbox versions from backports if available.

Do you reckon I should do a full-upgrade? It broke my system back in the day with Devuan jessie. Since then, I only use safe-upgrade and it does the job.

Last edited by HextorBRX (2019-01-09 17:01:39)

thierrybo · 2019-01-09 18:54:07

It is more harmful to activate backports, install packages from it and unactivate it afterwards because it might cause dependencies conflicts for further updates as in this other thread I answered this week. As a rule of thumbs, as long as you have at least ONE package installed from backports, keep the repository activated.

I always do a full-upgrade on stable, but I would not do that if I was using testing/unstable. However I ALWAYS read the command result before typing YES to see if it will not remove a bunch of packages. I had an issue one time where I did not read it and after running the command, even xorg was removed! So if you read carefully each command result before accepting it should be safe on "stable". If you feel uncomfortable with it, use just upgrade ( I believe "safe-upgrade" id for Aptitude).

By the way before using Debian and Devuan I used synaptic for ten years on Ubuntu, and in Synaptic the default was "Smart Upgrade" ( = full-upgrade).

Last edited by thierrybo (2019-01-09 19:00:43)

HextorBRX · 2019-01-10 21:07:30

Thank you guys for your answers. Just in case a beginner needs this thread, what I wrote above is ambiguous. Correct me if I'm wrong, most people don't need to enable source repositories such as deb-src blablabla ascii-backports. In any case, they are deactivated by default.

apt upgrade = aptitude safe-upgrade
apt dist-upgrade = aptitude full-upgrade and I don't feel comfortable with it.
However, I would say that those who need backports should use aptitude to resolve dependencies.

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#1 2019-01-07 14:00:24

backports: how to prevent incompatibilities?

#2 2019-01-07 15:36:26

Re: backports: how to prevent incompatibilities?

#3 2019-01-07 20:28:01

Re: backports: how to prevent incompatibilities?

#4 2019-01-07 21:55:31

Re: backports: how to prevent incompatibilities?

#5 2019-01-07 23:26:28

Re: backports: how to prevent incompatibilities?

#6 2019-01-07 23:48:55

Re: backports: how to prevent incompatibilities?

#7 2019-01-08 16:21:08

Re: backports: how to prevent incompatibilities?

#8 2019-01-08 16:49:38

Re: backports: how to prevent incompatibilities?

#9 2019-01-08 21:33:59

Re: backports: how to prevent incompatibilities?

#10 2019-01-08 21:36:33

Re: backports: how to prevent incompatibilities?

#11 2019-01-08 22:24:59

Re: backports: how to prevent incompatibilities?

#12 2019-01-08 22:41:00

Re: backports: how to prevent incompatibilities?

#13 2019-01-09 16:34:59

Re: backports: how to prevent incompatibilities?

#14 2019-01-09 18:54:07

Re: backports: how to prevent incompatibilities?

#15 2019-01-10 21:07:30

Re: backports: how to prevent incompatibilities?

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