@@ -882,17 +882,23 @@ private static bool ToArray(IntPtr value, Type obType, out object result, bool s
882882// See https://docs.microsoft.com/en-us/dotnet/api/system.type.makegenerictype#System_Type_MakeGenericType_System_Type
883883var constructedListType = typeof ( List < > ) . MakeGenericType ( elementType ) ;
884884bool IsSeqObj = Runtime . PySequence_Check ( value ) ;
885+ object [ ] constructorArgs = Array . Empty < object > ( ) ;
885886if ( IsSeqObj )
886887{
887888var len = Runtime . PySequence_Size ( value ) ;
888- list = ( IList ) Activator . CreateInstance ( constructedListType , new Object [ ] { ( int ) len } ) ;
889- }
890- else
891- {
892- // CreateInstance can throw even if MakeGenericType succeeded.
893- // See https://docs.microsoft.com/en-us/dotnet/api/system.activator.createinstance#System_Activator_CreateInstance_System_Type_
894- list = ( IList ) Activator . CreateInstance ( constructedListType ) ;
889+ if ( len >= 0 )
890+ {
891+ constructorArgs = new object [ ] { len } ;
892+ }
893+ else
894+ {
895+ // for the sequences, that explicitly deny calling __len__()
896+ Exceptions . Clear ( ) ;
897+ }
895898}
899+ // CreateInstance can throw even if MakeGenericType succeeded.
900+ // See https://docs.microsoft.com/en-us/dotnet/api/system.activator.createinstance#System_Activator_CreateInstance_System_Type_
901+ list = ( IList ) Activator . CreateInstance ( constructedListType , args : constructorArgs ) ;
896902}
897903catch ( Exception e )
898904{