The script at the very below defines 10 `Polyhedra` particles falling on a ground `Wall`. While behavior (in sequential execution) is not fully reproducible, it ends very often (let say 9 times out of 10) in less than a minute with some segfault-like crash (message varies around `Segmentation fault (core dumped)`) that comes from - `Ig2_Wall_Polyhedra_PolyhedraGeom::go` - then, because of [that](https://gitlab.com/yade-dev/trunk/-/blob/a37d9fd2f20f102fd277ac6aaaf52df8fbeb18f0/pkg/dem/Polyhedra_Ig2.cpp#L238), a `Polyhedron_Plane_intersection` function defined [here](https://gitlab.com/yade-dev/trunk/-/blob/a37d9fd2f20f102fd277ac6aaaf52df8fbeb18f0/pkg/dem/Polyhedra_support.cpp#L544) - then, because of [that](https://gitlab.com/yade-dev/trunk/-/blob/a37d9fd2f20f102fd277ac6aaaf52df8fbeb18f0/pkg/dem/Polyhedra_support.cpp#L606), a `Simplify` function defined [here](https://gitlab.com/yade-dev/trunk/-/blob/a37d9fd2f20f102fd277ac6aaaf52df8fbeb18f0/pkg/dem/Polyhedra_support.cpp#L321) - then, some CGAL `*Halfedge*` function For convenience, here are first some terminal commands to automatically execute the script after downloading vertices coordinates from the internet: ```bash mkdir test && cd test wget https://nextcloud.inrae.fr/s/Ca5aXq8jx7Py2Xa/download/ig2wallpoly.tar # vertices data file and yade script tar xvf ig2wallpoly.tar && rm ig2wallpoly.tar yadedaily ig2wallpoly.py # or yade ``` And finally, that `ig2wallpoly.py` that crashes with yade versions spanning from `yade # 2018.02b` to `yadedaily # 20210703-5497~a37d9fd~focal1` and CGAL 4.11 to 5.02 Having confirmation (in addition to @schd, thank you Sacha) of the crash would already be something. ```python # falling polyhedral particles (10 of them) that shows a crash coming from Ig2_Wall_Polyhedra_PolyhedraGeom ################################# ### An initial handy function ### ################################# def read3colTxtFile(fileObj,header=0): '''Reads a 3 columns text file with numeric data, e.g. a list of points in 3D space. :param fileObj: the file object such as returned by open(path,'r') :param header: how many header lines there is (and you do not want to read) :returns: a list (of 3 elements list) of points ''' wholeFile = fileObj.read() lines = wholeFile.splitlines()[header:] lPts=[] for line in lines: strPt = line.split() lPts.append([float(strPt[i]) for i in range(3)]) return lPts ######################### ### Engine definition ### ######################### O.engines=[ForceResetter() ,InsertionSortCollider([Bo1_Polyhedra_Aabb(),Bo1_Wall_Aabb()],verletDist = 0) ,InteractionLoop( [Ig2_Polyhedra_Polyhedra_PolyhedraGeom(),Ig2_Wall_Polyhedra_PolyhedraGeom()], [Ip2_PolyhedraMat_PolyhedraMat_PolyhedraPhys()], [Law2_PolyhedraGeom_PolyhedraPhys_Volumetric(volumePower=1./3.)] ) ,NewtonIntegrator(damping=0.3,label='newton',gravity = (0,0,-9.8)) ] O.dt = 25*1.e-6 ######################### ### Bodies definition ### ######################### O.materials.append(PolyhedraMat(density=2650,frictionAngle=radians(25),young=2.e5,poisson=0.7)) for cpt in range(10): # defining 10 polyhedra that will fall O.bodies.append(polyhedron(read3colTxtFile(open('vertBod'+str(cpt)+'.txt'),header=1))) O.bodies.append(wall( (0,0,0),2,sense=1 )) # a frictional ground wall ################ ### Let s go ### ################ O.save('ini.yade') yade.qt.Controller(),yade.qt.View() O.run(70000) # crash (e.g. segmentation fault, frozen Controller and terminal) usually happens before ```