[gentoo-science] sage queues

[VulK <etn45p4m@gmail.com>]

Dear all,
this is my first post to gentoo-science and I am writing because I have some
problems running experimental code from the sage project.
My issue is the following:
I have sci-mathematics/sage-4.7-r2 installed from the  sage-on-gentoo overlay
and I would like to install the combinat queue; I am following these
instructions: http://wiki.sagemath.org/combinat/MercurialStepByStep
The command I am supposed to run is 
# sage -combinat install
unfortunately -combinat is not recognized by sage as a valid option. I
browsed a little bit around the filesystem and I noticed that $SAGE_ROOT is
empty (except for some documentation) while on other installations of sage
(not using the ebuilds) there is plenty of stuff including a devel/combinat
folder.
Is there an option I can use when installing sage to allow for experimental
sources? or is there any other way I can use queues without installing sage
not using portage?
Thanks
VulK

PS: some weird behaviour:

% sage -h
----------------------------------------------------------------------
| Sage Version 4.7, Release Date: 2011-05-23                         |
----------------------------------------------------------------------

Optional arguments:
  file.<sage|py|spyx> -- run given .sage, .py or .spyx files
  -advanced           -- list all command line options
  -c <cmd>            -- Evaluates cmd as sage code
  -experimental       -- list all experimental packages that can be installed
  -gap [...]          -- run Sage's Gap with given arguments
  -gp [...]           -- run Sage's PARI/GP calculator with given arguments
  -h, -?              -- print this help message
  -i [packages]       -- install the given Sage packages
  -inotebook [...]    -- start the *insecure* Sage notebook
  -maxima [...]       -- run Sage's Maxima with given arguments
  -mwrank [...]       -- run Sage's mwrank with given arguments
  -n, -notebook [...] -- start the Sage notebook (options are the same
                         as for the notebook command in Sage)
  -optional           -- list all optional packages that can be installed
  -python [...]       -- run the Python interpreter
  -R [...]            -- run Sage's R with given arguments
  -singular [...]     -- run Sage's singular with given arguments
  -root               -- print the Sage root directory
  -t [options] <files|dir>
                      -- test examples in .py, .pyx, .sage or .tex files
                         options:
                           -long  -- include lines with the phrase 'long time'
                           -verbose  -- print debugging output during the test
                           -optional  -- also test all #optional examples
                           -only-optional <tag1,...,tagn>  -- only run tests
                            including one of the #optional tags
                           -randorder[=seed]  -- randomize order of tests
  -v, -version        -- print the Sage version

% sage -experimental
sage-run received unknown option: -experimental 
usage: sage [options]
Try 'sage -h' for more information.