Several environment variables are required:
$HARPO_USER_DIR/lib needs to be added to the library path ($LD_LIBRAY_PATH. Example of configuration:
export HARPO_DATA_DIR=/net/llrdata1.in2p3.fr/data/DATA/data.harpo/2012/Daq
export HARPO_RECO_DIR=/net/llrdata1.in2p3.fr/data/DATA/data.harpo/2012/Reco
export HARPO_USER_DIR=$HOME/Harpo/
export HARPO_ANA_DIR=$HOME/HarpoAnalysis/
export LD_LIBRARY_PATH=${HARPO_USER_DIR}/lib:${LD_LIBRARY_PATH}
export PATH=${HARPO_USER_DIR}/bin:${PATH}