QGIS » QGIS Application

1) I used 2 input polygon-layers (shp-datasource)

2.1) with each: “processing ...native:fixgeometries”
2.2) with each result: “ processing ... qgis:checkvalidity”
2.3) with resulting valid layers: save as shp
2.4) with each layer: “processing....qgis:snapgeometries” (one layer as input / other as reference-layer, tolerance=0.3, behaviour: prefer nodes,add vertices; temporary layer) -> crash at 1%

Report:
Crash ID: b4b7a7ecd21274bc55969d96468662ce0cc371f4

Stack Trace

QgsCurvePolygon::vertexAt :
QgsGeometryCollection::vertexAt :
QgsGeometrySnapper::snapGeometry :
QgsGeometrySnapper::snapGeometry :
PyInit__analysis :
PyCFunction_FastCallDict :
PyObject_GenericGetAttr :
PyEval_EvalFrameDefault :
PyFunction_FastCallDict :
PyObject_CallFunctionObjArgs :
PyObject_Call :
PyInit_sip :
std::basic_string,std::allocator >::shrink_to_fit :
std::_String_alloc > >::_Get_data :
QgsProcessingAlgorithm::runPrepared :
QgsProcessingAlgRunnerTask::run :
PyInit__core :
QgsTask::start :
QThreadPoolPrivate::reset :
QThread::start :
BaseThreadInitThunk :
RtlUserThreadStart :

QGIS Info
QGIS Version: 3.0.0-Girona
QGIS code revision: 001c80b0c3
Compiled against Qt: 5.9.2
Running against Qt: 5.9.2
Compiled against GDAL: 2.2.3
Running against GDAL: 2.2.3

System Info
CPU Type: x86_64
Kernel Type: winnt
Kernel Version: 6.3.9600