It also depends on nodejs at runtime, to compile the less files.
It appears that it wants to write the generated files to site-packages at run time, too.
/var/tmp/portage/www-apps/horizon-2013.1.2/image/usr/lib64/python2.7/site-packages/bin/less is a directory I don't think the nodejs stuff is necessary as a dep though The writing of the generated package is bothersome though. I kinda want to remove this package as it's one of the less well put together package for openstack... Maybe havana or the 'i' release will be better...
I don't see any more nodejs in 2013.2.9999 so closing :D