  Hadron generation models are indispensable for the simulation and calibration
of particle physics detectors. The models used by the Geant4 simulation tool
kit are compared with inclusive spectra of secondary protons and pions from the
interactions with beryllium nuclei of +8.9 GeV/c protons and pions, and of -8.0
GeV/c pions. We report on significant disagreements between data and model
predictions especially in the polar-angle distributions of secondary protons
and pions.
