Problem compiling GUI (sip related)

While compiling GUI on Gentoo Linux I get the following error message:
It seems to be sip related (I have sip 4.2.1). Any help is welcome...

       Daniel

make[3]: Leaving directory `/var/tmp/portage/sci-misc/salome-gui-3.2.6/work/salome3.2.6_SRC/GUI_SRC_3.2.6/src/SALOME_PY'
+ for d in Qtx Style DDS QDS SUIT STD CAF CAM SUITApp LogWindow ObjBrowser Prs OBJECT GLViewer VTKViewer SVTK OCCViewer SOCC PyInterp PythonConsole Plot2d SPlot2d SUPERVGraph LightApp ResExporter RegistryDisplay TOOLSGUI Event Session SalomeApp SALOME_SWIG SALOME_PY SALOME_PYQT
+ cd SALOME_PYQT
+ make depend
make[3]: Entering directory `/var/tmp/portage/sci-misc/salome-gui-3.2.6/work/salome3.2.6_SRC/GUI_SRC_3.2.6/src/SALOME_PYQT'
+ for d in SALOME_PYQT_GUI SalomePyQt
+ cd SALOME_PYQT_GUI
+ make depend
make[4]: Entering directory `/var/tmp/portage/sci-misc/salome-gui-3.2.6/work/salome3.2.6_SRC/GUI_SRC_3.2.6/src/SALOME_PYQT/SALOME_PYQT_GUI'
/usr/bin/sip -t WS_X11 -t Qt_3_3_8 -x Qt_STYLE_INTERLACE -x Qt_STYLE_WINDOWSXP -s ".cc" -c . -I /usr/share/sip/qt SALOME_PYQT_GUI.sip
sip: /usr/share/sip/qt/versions.sip:30: Exactly one of this %Timeline must be specified with the -t flag
make[4]: *** No rule to make target `.depend', needed by `depend'.  Stop.
make[4]: Leaving directory `/var/tmp/portage/sci-misc/salome-gui-3.2.6/work/salome3.2.6_SRC/GUI_SRC_3.2.6/src/SALOME_PYQT/SALOME_PYQT_GUI'
+ exit 1
make[3]: *** [depend] Error 1
make[3]: Leaving directory `/var/tmp/portage/sci-misc/salome-gui-3.2.6/work/salome3.2.6_SRC/GUI_SRC_3.2.6/src/SALOME_PYQT'
+ exit 1
make[2]: *** [depend] Error 1
make[2]: Leaving directory `/var/tmp/portage/sci-misc/salome-gui-3.2.6/work/salome3.2.6_SRC/GUI_SRC_3.2.6/src'
+ exit 1
make[1]: *** [depend] Error 1
make[1]: Leaving directory `/var/tmp/portage/sci-misc/salome-gui-3.2.6/work/salome3.2.6_SRC/GUI_SRC_3.2.6'
make: *** [all] Error 2
make: INTERNAL: Exiting with 2 jobserver tokens available; should be 3!