TabBarView inside a Positioned error Horizontal viewport was given unbounded height - Flutter

I'm getting the error below when I try to run the code. I need the Containers inside the TabBarView to have their sizes set to (200 and 150), but I can't make it happen. My code only stops breaking when I use Positioned.fill or wrap the TabBarView in an Expanded, forcing the maximum height. However, I need the children of the TabBarView to have their minimum size, I've tried wrapping the TabBarView in a column and passing MainAxisSize.min, but I haven't had success either. Does anyone know what I can do to make the children's sizes have their minimum height? Note: I need to use two Positioned in this case.

> FlutterError (Horizontal viewport was given unbounded height.
Viewports expand in the cross axis to fill their container and constrain their children to match their extent in the cross axis. In this case, a horizontal viewport was given an unlimited amount of vertical space in which to expand.)

Scaffold(
      backgroundColor: Colors.grey,
      appBar: AppBar(),
      body: SafeArea(
        child: Stack(
          children: [
            Positioned( // <--  Not using Positioned.fill
              top: 43,
              left: 0,
              right: 0,
              child: TabBarView( // <-- And not using Expanded there, the children of TabBarView is not expanded, need min size
                controller: _tabController,
                children: [
                  Container(height: 200,
               decoration: BoxDecoration(borderRadius: 
               BorderRadius.circular(15.0),                           
            color:Theme.of(context).colorScheme.surface,
                              ),),
                  Container(height: 150,color: Colors.green),
                ],
              ),
            ),
            Positioned(
              top: 0,
              left: 0,
              right: 0,
              child: TabBar(
                controller: _tabController,
                tabs: const [
                  Tab(text: 'Tab 1'),
                  Tab(text: 'Tab 2'),
                ],
              ),
            ),
          ],
        ),
      ),
    );

Hope this helps.

I am not sure why Stack is required here. If it's mandatory, let me know. The below code and inline comment will help you understand using TabBarView in a better way.

Tip 1: You need either Expanded or Flexible to wrap your TabBarView to make it work as TabBarView has unbounded height

Tip 2: Wrap your TabBarView containers with Column and mention to keep the size as min.

return Scaffold(
      backgroundColor: Colors.grey,
      appBar: AppBar(),
      body: SafeArea(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            TabBar(
              controller: _tabController,
              tabs: const [
                Tab(text: 'Tab 1'),
                Tab(text: 'Tab 2'),
              ],
            ),
            Flexible(
              //Use Flexible instead of Expanded to shrink the height based on the children heights

              child: TabBarView(
                // <-- And not using Expanded there, the children of TabBarView is not expanded, need min size
                controller: _tabController,
                children: [
                  Column(
                    mainAxisSize: MainAxisSize
                        .min, //Wrap your view container with Column and mention to keep the size as min
                    children: [
                      Container(
                        decoration: const BoxDecoration(
                          color: Colors.black54,
                          borderRadius: BorderRadius.only(
                            topRight: Radius.circular(20),
                          ),
                        ),
                        height: 200,
                      ),
                    ],
                  ),
                  Column(
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      Container(
                        decoration: const BoxDecoration(
                          color: Colors.black54,
                          borderRadius: BorderRadius.only(
                            topLeft: Radius.circular(20),
                          ),
                        ),
                        height: 150,
                      ),
                    ],
                  ),
                ],
              ),
            ),
          ],
        ),
      ),
    );