1

I have a pending update for "Get Hot New Stuff" for the KDE Platform (libknewstuff2-4).

I don't recall installing anything with KDE dependencies (I'm using vanilla Ubuntu), so I tried to figure out why it's there.

I found that I can use

apt-cache rdepends --installed libknewstuff2-4

to find installed packages that depend on this. This leads me to the package python-kde4. Upstream of this package are: python-qt4 and python-keyring.

At this point, things get hard to follow. qt-4 seems to have a circular dependency back to python-kde4. I think I can trace -keyring back to bzr, but I also see python-crypto upstream from -keyring. -crypto has more rdepends than I care to investigate...

Is there a better way to understand what's going on here? Alternatively, does it make sense that I'm getting kde libraries based on a package that isn't KDE specific (like bzr)?

EDIT: Using aptitude why as recommended below seems to automate what I manually did with apt-cache:

$ aptitude why libknewstuff2-4 
i   bzr                 Depends    python-bzrlib (>= 2.6.0+bzr6593-1ubuntu1.1)
i A python-bzrlib       Recommends python-launchpadlib                        
i A python-launchpadlib Depends    python-keyring (>= 0.5)                    
i A python-keyring      Suggests   python-kde4                                
i A python-kde4         Depends    libknewstuff2-4 (>= 4:4.13.3)

Although I'm not sure what the "Recommends" and "Suggests" states mean. The man page says:

Note that the dependency that aptitude produced in this case is only a suggestion. This is because no package currently installed on this computer depends on or recommends the ... package; if a stronger dependency were available, aptitude would have displayed it.

So what does it really mean that python-keyring "suggests" python-kde4, and do I have a choice in pulling in this "dependency"?

Braiam
  • 67,791
  • 32
  • 179
  • 269
jake
  • 449
  • 2
  • 4
  • 12
  • 1
    Try aptitude why - it might give simpler results. – muru Dec 02 '14 at 02:07
  • A suggests type dependency is the weakest type, it should be safe to remove. – CameronNemo Dec 02 '14 at 03:11
  • 1
    @muru I ended up apt-get removing bzr based on what I saw in aptitude why. When I reinstalled it, it didn't pull in the "Suggested" packages and so therefore solved my problem. Please repost aptitude why as an answer. – jake Dec 02 '14 at 14:46
  • It's already an answer here: http://askubuntu.com/questions/5636/can-i-see-why-a-package-is-installed, and the question is sufficiently similar that I'll mark it as a duplicate instead. – muru Dec 02 '14 at 14:52
  • You can remove "python-kde4" without problems. Is just a suggested package. – Braiam Dec 08 '14 at 23:56

1 Answers1

0

Another way to find out why this was installed would be to zgrep libknewstuff2 /var/log/apt/* (you may have to use sudo). The hits might give you some hints as to why this got installed...

Jan
  • 12,291
  • 3
  • 32
  • 38
  • I think that this points to pretty close to the time that I originally installed Ubuntu. Any way I can use that to help narrow this down? – jake Dec 02 '14 at 02:00
  • Well, installation timestamps close to identical would perhaps have given a clue... But if it got installed initially then I guess it's not useful in your case. – Jan Dec 02 '14 at 22:20