[BUG] Pinch zoom gesture causes an exception

[ultrapoci]

I've copy pasted this code from the example directory:

Chart(
    data: scatterData,
    variables: {
      '0': Variable(
        accessor: (List datum) => datum[0] as num,
      ),
      '1': Variable(
        accessor: (List datum) => datum[1] as num,
      ),
      '2': Variable(
        accessor: (List datum) => datum[2] as num,
      ),
      '4': Variable(
        accessor: (List datum) => datum[4].toString(),
      ),
    },
    marks: [
      PointMark(
        size: SizeEncode(variable: '2', values: [5, 20]),
        color: ColorEncode(
          variable: '4',
          values: Defaults.colors10,
          updaters: {
            'choose': {true: (_) => Colors.red}
          },
        ),
        shape: ShapeEncode(variable: '4', values: [
          CircleShape(hollow: true),
          SquareShape(hollow: true),
        ]),
      )
    ],
    axes: [
      Defaults.horizontalAxis,
      Defaults.verticalAxis,
    ],
    coord: RectCoord(
      horizontalRange: [0.05, 0.95],
      verticalRange: [0.05, 0.95],
      horizontalRangeUpdater: Defaults.horizontalRangeEvent,
      verticalRangeUpdater: Defaults.verticalRangeEvent,
    ),
    selections: {'choose': PointSelection(toggle: true)},
    tooltip: TooltipGuide(
      anchor: (_) => Offset.zero,
      align: Alignment.bottomRight,
      multiTuples: true,
    ),
  ),
),

It is supposed to handle zoom and panning, and it works, but the moment I do a somewhat "extreme" gesture (like zooming too much or doing a rotation with the two fingers of 360°) the program crashes due to an exception: [ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: RangeError (index): Invalid value: Not in inclusive range 0..99: -1.

I have no idea how to solve this issue.