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TheGeeko61
Asked: 2011-12-22 19:28:37 +0800 CST

How paranoid should I be that the automatic package manager mechanism is going to remove packages that I use?

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When I use the packaging tool, it "reminds" me to use autoremove to remove packages which are no longer needed. But when I review the list, I see packages which I wish to keep.

$ sudo apt-get install gnome-tweak-tool
Reading package lists... Done
Building dependency tree       
Reading state information... Done
gnome-tweak-tool is already the newest version.
The following packages were automatically installed and are no longer required:
  ekiga libopal3.10.2 gnome-backgrounds gtali glchess gnome-games cheese gdebi
  gnobots2 gnome-icon-theme-extras libcheese-gtk20 libcheese1 gdebi-core
  libcapi20-3 gnibbles gnuchess-book libpt2.10.2 libcluttergesture-0.0.2-0
  gnotski gir1.2-gucharmap-2.90 libclutter-imcontext-0.1-0 libspandsp2
  cheese-common sound-juicer iagno glines libmx-1.0-2 libfolks-eds25
  gnome-contacts gedit-plugins liferea gnotravex gnect quadrapassel
  liferea-data gnuchess gnome-video-effects
Use 'apt-get autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

For example, in the above list, gnuchess and gnuchess-book are identified. I don't wish for them to be removed.

QUESTION: Are these metapackages that I need not fight (with apt) to defend from removal? Will I lose the ability to play glchess?

NB. I used gnome-tweak-tool as an example in the commandline, knowing that it was already installed. This is irrelevant to my question.

11.10

1 Answers

  1. Best Answer

    You don't need to be paranoid, you just need to read and comprehend what apt-get is telling you. Obviously, if you remove glchess, you will lose the ability to play glchess!

    At some stage you must have removed a package (probably a metapackage) which depends on some or all of the packages you see.

    To figure out which metapackage this might be, you can use apt-rdepends. This tool can look up "reverse-dependencies", or packages which depend on a given package.

    For example, for the package gnome-backgrounds:

    $ apt-rdepends -r gnome-backgrounds
Reading package lists... Done
Building dependency tree       
Reading state information... Done
gnome-backgrounds
  Reverse Depends: gnome-core (>= 1:3.0+1ubuntu1)
gnome-core
  Reverse Depends: gnome (= 1:3.0+1ubuntu1)
gnome
  Reverse Depends: gnome-desktop-environment (>= 1:3.0+1ubuntu1)
gnome-desktop-environment

    This shows that gnome-backgrounds is depended upon by a single package, gnome-core, which in turn is depended upon by gnome, which in turn is depended upon by gnome-desktop-environment which no other packages depend upon.

    Now you can find out about these packages:

    $ aptitude show gnome-core gnome gnome-desktop-environment

    You will see that these are all meta-packages, and on your system at least one has been removed. You can then:

    • Try to apt-get install the 'lowest' dependency, in this case gnome-core. However this may pull in additional packages that you don't actually want to install (read what apt-get says, don't just hit enter).
    • If you don't want everything the meta-packages would install, and you want to keep all the packages, just run aptitude keep-all. This will mark the outstanding packages as 'installed', and apt-get will stop reminding you about them.
    • If you only want some of the packages, you can apt-get install them before running apt-get autoremove. You'll have to read the package descriptions to decide which ones you want.

    I think the main point here is that apt-get is just a tool. It doesn't know what you really want, it just does what you tell it. For this reason you should never blindly trust it to do the 'right thing', because often this is not the same as what you told it to do! This is doubly important to keep in mind when running sudo commands, since it's so easy to do catastrophic damage to your system.

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