no theme named 'ecto_theme' found

edit

i'm following the instructions at this link to install object_recognition_core . When i try to:

make sphinx-doc

it returns the following error:

 asaad@VAIO:~/ork/build$ make sphinx-doc
Running Sphinx v1.1.3
SYS.PATH=== ['/usr/share/sphinx/scripts/python2', '/home/asaad/ork/devel/lib/python2.7/dist-packages', '/home/asaad/moveit/devel/lib/python2.7/dist-packages', '/opt/ros/hydro/lib/python2.7/dist-packages', '/usr/lib/python2.7', '/usr/lib/python2.7/plat-linux2', '/usr/lib/python2.7/lib-tk', '/usr/lib/python2.7/lib-old', '/usr/lib/python2.7/lib-dynload', '/usr/local/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages', '/usr/lib/python2.7/dist-packages/PIL', '/usr/lib/python2.7/dist-packages/gst-0.10', '/usr/lib/python2.7/dist-packages/gtk-2.0', '/usr/lib/pymodules/python2.7', '/usr/lib/python2.7/dist-packages/ubuntu-sso-client', '/usr/lib/python2.7/dist-packages/ubuntuone-client', '/usr/lib/python2.7/dist-packages/ubuntuone-control-panel', '/usr/lib/python2.7/dist-packages/ubuntuone-couch', '/usr/lib/python2.7/dist-packages/ubuntuone-installer', '/usr/lib/python2.7/dist-packages/ubuntuone-storage-protocol', '/usr/lib/python2.7/dist-packages/wx-2.8-gtk2-unicode', '/home/asaad/ork/src/object_recognition_ros_visualization/doc/source']

Theme error:
no theme named 'ecto_theme' found (missing theme.conf?)
make[3]: *** [object_recognition_ros_visualization-sphinx] Error 1
make[2]: *** [object_recognition_ros_visualization/CMakeFiles/object_recognition_ros_visualization-sphinx.dir/all] Error 2
make[1]: *** [object_recognition_core/CMakeFiles/sphinx-doc.dir/rule] Error 2
make: *** [sphinx-doc] Error 2

i've tried cloning ecto from this link but still get the same error when i try make sphinx-doc.

I'm using ubuntu 12.04 & ROS Hydro.