FlatButton margin changed after a Flutter Upgrade - flutter

Question

I have run a Flutter Upgrade and it has caused a regression on one of my Layout.
Here is the code:
Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
FlatButton(
child: Icon(
Icons.remove,
color: Colors.black,
),
onPressed: () {
setState(() {
if (_debitValue > 1) _debitValue--;
});
},
),
Slider(
value: _debitValue.toDouble(),
min: 1.0,
max: 100.0,
onChanged: (double value) {
setState(() {
_debitValue = value.toInt();
});
},
),
FlatButton(
child: Icon(
Icons.add,
color: Colors.black,
),
onPressed: () {
setState(() {
if (_debitValue <100) _debitValue++;
});
},
),
],
),
This is a row with a '-' button, then a slider, then a '+' button.
It was displayed fine. Yesterday I have done a Flutter Upgrade and it now exceeds the width of the screen by 8 pixels. It says:
I/flutter (13431): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter (13431): The following message was thrown during layout:
I/flutter (13431): A RenderFlex overflowed by 8.0 pixels on the right.
I/flutter (13431):
I/flutter (13431): The overflowing RenderFlex has an orientation of Axis.horizontal.
I/flutter (13431): The edge of the RenderFlex that is overflowing has been marked in the rendering with a yellow and
I/flutter (13431): black striped pattern. This is usually caused by the contents being too big for the RenderFlex.
I/flutter (13431): Consider applying a flex factor (e.g. using an Expanded widget) to force the children of the
I/flutter (13431): RenderFlex to fit within the available space instead of being sized to their natural size.
I/flutter (13431): This is considered an error condition because it indicates that there is content that cannot be
I/flutter (13431): seen. If the content is legitimately bigger than the available space, consider clipping it with a
I/flutter (13431): ClipRect widget before putting it in the flex, or using a scrollable container rather than a Flex,
I/flutter (13431): like a ListView.
I have added some colors to see the margins used by the FlatButtons. They look pretty big. I have tried to change them but I didn't succeed. I have tried:
FlatButton(materialTapTargetSize: MaterialTapTargetSize.shrinkWrap, ...)
I have seen that I can use an Inkwell instead of a FlatButton. It works but the effect on the button is different and I would like to understand how to do it with a FlatButton.
Thanks for your advices

Answer 1

I haven't tested it but maybe something like this could work?
Row(
children: <Widget>[
Expanded(
child: FlatButton(
...,
),
flex: 1,
),
Expanded(
child: Slider(
...,
),
flex: 4, //maybe play with this value to see what looks best
),
Expanded(
child: FlatButton(
...,
),
flex: 1,
),
],
),