The taskmanager API in kde-workspace got some cleanup (see commits today). Part of the cleanup involved removing the TaskDict typedef, and replacing it with a QHash<> type. KTorrent uses TaskDict to iterate the running tasks (see ktorrent/plasma/applet/applet.cpp:344) and therefor the build fails. This should either be adapted to the API change, or (better) be replaced with a D-Bus method to check for the already running application and activate it. It is probably simplest to check how KUniqueApplication does it.
According to plasma developers, libtaskmanager API should not be used outside of kde-workspace and kdeplasma-addons.
Git commit 6d4a6ae51692966862ccb20d17cb217717519d40 by Joris Guisson. Committed on 23/11/2011 at 20:17. Pushed by guisson into branch 'master'. Use dbus to show ktorrent window from plasma applet. This removes the dependency on libtaskmanager. BUG: 287309 M +1 -0 ChangeLog M +10 -20 plasma/applet/CMakeLists.txt M +40 -16 plasma/applet/applet.cpp M +2 -0 plasma/applet/applet.h http://commits.kde.org/ktorrent/6d4a6ae51692966862ccb20d17cb217717519d40