Segmentation fault

Dear all,
I wanna run a model that is a big boulder dropping into the granular,
but I am always failed..I wanna try only the dropping model 1st, if it works, then I can assign some states...
could anyone help me to solve the problem?

this is my code

##Define Geometry
O.bodies.append([utils.sphere(center=(.35,-.35,2),radius=.3)])

##Sphere pack in box shape
#noTableOk=True,fixed=True
from yade import pack, timing
readParamsFromTable(num=12000)
sp=pack.SpherePack()
sp.makeCloud((-.1,.1,0),(.8,-.8,.5),.03*((12000./yade.params.table.num)**(1/3.)),.5)
sp.toSimulation()

##Wall
O.bodies.append(wall((0,0,0),axis=2))

##Engines and Constitutive Law
O.engines=([SubdomainBalancer(axesOrder='xyz',colorize=True)] if
'SubdomainBalancer' in dir() else [])+[ForceResetter(),
InsertionSortCollider([Bo1_Sphere_Aabb(),Bo1_Sphere_Aabb(),Bo1_Wall_Aabb()],verletDist=.05*.05),
InteractionLoop([Ig2_Sphere_Sphere_ScGeom(),Ig2_Sphere_Sphere_ScGeom(),Ig2_Wall_Sphere_ScGeom()],
[Ip2_FrictMat_FrictMat_FrictPhys()],[Law2_ScGeom_FrictPhys_CundallStrack()]),
NewtonIntegrator(damping=0.1,gravity=[0,0,-9.81])]

O.dt=.01*PWaveTimeStep()

O.save('/tmp/c.xml.bz2');

Thank you for the attentions

Best regards.