1. You need a installed python(in your case Ruby) I have a own installed and compilled python. Please check the LD_LIBRAY_PATH and PATH. They have to be set correctly. They have to link the Ruby or python lib directory.
2. I downoaled INSTALL_QTROOT.sh from the http://root.bnl.gov/QtRoot/How2Install4Unix.html page. I had a root installation before and I setuped the ROOTSYS link the ROOT installed directory, but when I runned the script automatic removed the existing ROOT.

   If you want you can edit and change the qt or ROOT version.

3. you have to run this scripts. If you don't have qt installed version this scripts automatic install it. If you don't want a new qt installation please setup the existing qt. I have qt 4.4.3, 4.4.2, 4.5.2 installed version. I tried this scrip with qt4.4.2 and qt4.5.2 and it is worked fine.
4. You have to compile the qtRoot, before you have to setup the enviorement. Source set_environment.sh or set_environment.tcsh ...., it is depend which shell are you using.

   You have to download the qtRoot from CVS:

     -> cvs -d :pserver:cvsuser@cvs.bnl.gov:/data01/CVS login
             password: cvsuser
     -> cvs -d :pserver:cvsuser@cvs.bnl.gov:/data01/CVS co -d qtRoot root
     -> cd qtRoot
     -> qmake
     -> make
     -> make install
   

   I propose to test the qtRoot installation, because it is not working, then you will can not use qtRoot from python.

     ->cd qtExamples
     ->qmake
     ->make
   

5. you have to setup the pyROOT.

   I give an example:

   setenv ROOTSYS /scratch/zmathe/local/root
   setenv PYTHONPATH ${ROOTSYS}/lib:${PYTHONPATH}
   

   Then try the pyRoot:

     -> python
     -> import ROOT
   

6. Now you have qt-ROOT-qtRoot, but using the qtRoot from python dosn't work. You need a pyQt installed version.
   • -> download a pyQt( I have the last version)
   • -> compile with the your python and the qt root.

   DO NOT FORGET:

   If you have PyQt compiled version with a other qt, it will doesn't work. You have to be make sure you compiled the PyQt with the good qt version (You have to compile with qt used by qtRoot).

7. try to run qtexample.py

Cheers,
Zoltan