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"?
