Somehow I lost FindKDE4Internal.cmake, and I cannot figure out how to get it back. I know I need kdelibs5-dev for this, and KPackageKit says I have 4:4.4.2; It seems there is a conflict somewhere:

The following packages have unmet dependencies:
kdelibs5-dev: Depends: libplasma3 (= 4:4.4.2-0ubuntu4) but 4:4.5.3-0ubuntu1~lucid1~ppa1 is to be installed
Depends: automoc (>= 1.0~svn850570) but it is not going to be installed
Depends: libqt4-dev (>= 4:4.6.2) but it is not going to be installed
Depends: libsoprano-dev but it is not going to be installed
Depends: libphonon-dev (>= 4:4.6.2) but it is not going to be installed
Recommends: libqt4-opengl-dev (>= 4:4.6.2) but it is not going to be installed

How can I solve this?

You are using some kind of KDE unstable PPA, because it is looking for KDE 4.6.x packages.

Someone running Kubuntu might tell what you are doing wrong. I'd suggest you post your sources.list to tell where you are trying to upgrade from.

On a side note, kdelibs5 is the package name under Debian (and Ubuntu, et al) of the KDE4 packages. Weird, but that's the way it is.

I think it happened when I pulled Claydoh's KMM 4.5.2. I must have messed up trying to undo that. My sources.list contains only lines with "archive.ubuntu.com" or "security.ubuntu.com". However, sources.list.d is probably inconsistent:

claydoh-kmymoney2-kde4-lucid.list.save medibuntu.list opera.list
kubuntu-ppa-backports-lucid.list.save medibuntu.list.save opera.list.save

Thanks.

The kubuntu-ppa-backports has probably changed and now it has packages for KDE 4.6.x

Some Kubuntu user might help better with this.

Lucid does not have any KDE 4.6 packages available, either from the standard repos or a ppa. The items you are seeing at version 4.6 are Qt and libphonon.

Do make sure you update your package list as this is often the cause for this sort of error - the packages listed as 'to be installed' is from the Kubuntu backports ppa
https://launchpad.net/~kubuntu-ppa/+archive/backports,
simply removing the ppa listing itself does not update the package database, even if done so from KPAckageKit (which is a terrible tool in Lucid). You still need to update it. Very likely apt is looking for packages from that ppa for this reason. The 'foo.bar.list.save' entries in /etc/apt/sources.list.d are iirc just apt repo entries that have been disabled but not deleted, or they may be used as backups - they are not used.

Entries placed in the directory /etc/apt/sources.list.d are just an alternative way to add repositories without having to actually edit the original sources.list file itself.

I recommend updating from the command line or from another package manager such as Muon or Synaptic as the version of KPackageKit in Lucid is simply awful, I would not use it to determine the KDE version you are running either. If you are really at kde 4.5.3, you will need to add the kubuntu backports repo back in in order to get the needed packages. Check your true kde version from any KDE application's help menu.

Thanks, Clay! The missing file is back and I'm all set.