> /home/users/robert/LBT/tryton-trunk/trytond/trytond/model/fields/many2one.py(72)__set__()
-> assert isinstance(value, (Target, NoneType))
(Pdb) value
Pool().get('product.product-production.bom')(1)
(Pdb) Target
<class 'trytond.modules.production.bom.production.bom'>
(Pdb) bt
  /home/users/robert/LBT/tryton-trunk/trytond/trytond/protocols/jsonrpc.py(123)_marshaled_dispatch()
-> response['result'] = dispatch_method(method, params)
  /home/users/robert/LBT/tryton-trunk/trytond/trytond/protocols/jsonrpc.py(156)_dispatch()
-> res = dispatch(*args)
  /home/users/robert/LBT/tryton-trunk/trytond/trytond/protocols/dispatcher.py(151)dispatch()
-> result = rpc.result(meth(*args, **kwargs))
  /home/users/robert/LBT/tryton-trunk/trytond/trytond/wizard/wizard.py(259)execute()
-> return wizard._execute(state_name)
  /home/users/robert/LBT/tryton-trunk/trytond/trytond/wizard/wizard.py(285)_execute()
-> do_result = do(action)
  /home/users/robert/LBT/tryton-trunk/trytond/trytond/modules/stock_supply_production/production.py(211)do_create_()
-> Production.generate_requests()
  /home/users/robert/LBT/tryton-trunk/trytond/trytond/modules/stock_supply_production/production.py(96)generate_requests()
-> quantity, date, company)
  /home/users/robert/LBT/tryton-trunk/trytond/trytond/modules/stock_supply_production/production.py(125)compute_request()
-> state='request',
  /home/users/robert/LBT/tryton-trunk/trytond/trytond/model/modelstorage.py(1113)__init__()
-> super(ModelStorage, self).__init__(id, **kwargs)
  /home/users/robert/LBT/tryton-trunk/trytond/trytond/model/model.py(583)__init__()
-> setattr(self, name, value)
  /home/users/robert/LBT/tryton-trunk/trytond/trytond/model/model.py(625)__setattr__()
-> super(Model, self).__setattr__(name, value)
> /home/users/robert/LBT/tryton-trunk/trytond/trytond/model/fields/many2one.py(72)__set__()
-> assert isinstance(value, (Target, NoneType))