Comment 6 for bug 574287

I've tested this on current Debian testing, and the problem exists, but is less problematic, since there seems to be much less overlap in the Debian tasks.

However one example is if the tasks: ~t^desktop. ~t^gnome-desktop and ~t^laptop, are installed and then the ~t^laptop task is removed. This will result in the removal of e.g. wpasupplicant, network-manager and network-manager-gnome, all of which are also a part of the ~t^gnome-desktop task.
I will take this upstream to Debian.

I've been told that the package sets are indeed defined by tasksel, hence the apt task would be invalid.