rqt_publisher broken ('rospack' is not defined)

edit

Hi.

I cannot use rqt_gui since the last update. The topic drill down is updating without any results:

And when I click on refresh, I have this message:

Traceback (most recent call last):
  File "/opt/ros/hydro/lib/python2.7/dist-packages/rqt_publisher/publisher_widget.py", line 103, in _update_thread_run
    for base_type_str in rosmsg.list_msgs(package, rospack=rospack):
NameError: global name 'rospack' is not defined

I have just re-installed everything this weekend so my settings are clean (I already had this message before the update).

Thx for the support.

PS: rospack is installed.

EDIT1: as requested in the comments.

arnaud@hercules:~$ dpkg -p ros-hydro-rqt-publisher
Package: ros-hydro-rqt-publisher
Priority: extra
Section: misc
Installed-Size: 145
Maintainer: Dorian Scholz <<a href="mailto:scholz@sim.tu-darmstadt.de">scholz@sim.tu-darmstadt.de</a>>
Architecture: amd64
Version: 0.3.1-0raring-20131010-0322-+0000
Depends: python-rospkg, ros-hydro-qt-gui-py-common, ros-hydro-roslib, ros-hydro-rosmsg (>= 1.9.49), ros-hydro-rqt-gui, ros-hydro-rqt-gui-py, ros-hydro-rqt-py-common
Size: 21496
Description: rqt_publisher provides a GUI plugin for publishing arbitrary messages with fixed or computed field values.
Homepage: <a href="http://ros.org/wiki/rqt_publisher">http://ros.org/wiki/rqt_publisher</a>