However, I also get an error when trying to compile the package into the IDE. When trying to install from the package list I get the following message after hitting the recompile IDE button:
lazarus.pp(1,1) Fatal: Cannot find anchordockingdsgn used by Lazarus. Check if package AnchorDockingDsgn creates anchordockingdsgn.ppu, check nothing deletes this file and check that no two packages have access to the unit source.
You may have mixed sources. The error message is misleading. It finds the file but it is wrong version.
You should start with a single Lazarus version. Later when you know what you are doing you can have more.
So I tried to load the package manually Package -> Open Package File... and install it from there. After being prompted to rebuild the IDE I get the same error.
Does the package compile?
Indeed the ppu file does not seem to be created. One reason I could think of is that compilation is against Qt4 on KDE. Could that be the problem?
Yes it is created but into a local config dir under your home dir, normally ~/.lazarus. That's because the original source dir is write-protected.
Qt4 has no effect here. It could only cause a linker error later if the QtPas libs are not found.
BTW, remember to use "startlazarus" for starting once you get the compilation right.