On alpha3 my ubiquity log is as follows:

Ubiquity 2.1.28
trying to create local folder /var/tmp/kdecache-root/kpc: Permission denied
trying to create local folder /var/tmp/kdecache-root/kpc: Permission denied
trying to create local folder /var/tmp/kdecache-root/kpc: Permission denied
trying to create local folder /var/tmp/kdecache-root/kpc: Permission denied
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
kubuntu-ubiquity(3258): Couldn't create index file "/var/tmp/kdecache-root/kpc/kde-icon-cache.index"
QInotifyFileSystemWatcherEngine::addPaths: inotify_add_watch failed: Permission denied
QFileSystemWatcher: failed to add paths: /root/.config/ibus/bus
Bus::open: Can not get ibus-daemon's address.
IBusInputContext::createInputContext: no connection to ibus-daemon
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
trying to create local folder /var/tmp/kdecache-root/kpc: Permission denied
trying to create local folder /var/tmp/kdecache-root/kpc: Permission denied
trying to create local folder /var/tmp/kdecache-root/kpc: Permission denied
trying to create local folder /var/tmp/kdecache-root/kpc: Permission denied
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
kubuntu-ubiquity(3258): Couldn't create index file "/var/tmp/kdecache-root/kpc/kde-icon-cache.index"
FIXME, medianotifier unload port to KDE 4
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
kubuntu-ubiquity(3258): Failed to lock file "/var/tmp/kdecache-root/kpc/kde-icon-cache.lock" , last result = 2
KCrash: Application '' crashing...
Warning: connect() failed: : Permission denied
KCrash cannot reach kdeinit, launching directly.
QSocketNotifier: Invalid socket 13 and type 'Read', disabling...
drkonqi(4104) SystemInformation::runLsbRelease: found lsb_release
drkonqi(4104) KCrashBackend::constructCrashedApplication: Executable is: "/usr/bin"
drkonqi(4104) KCrashBackend::constructCrashedApplication: Executable exists: true
drkonqi(4104): The specified process does not exist.