I'm playing with constraints to see how it works so I set the minWidth to

200.ipx

and MaxWidth to 300.ipx but the when I print the constraints minWidth is

0.ipx

, MaxWidth's value is 300.ipx as expected.

WithConstraints { constraints ->
        Log.d("Constraints", constraints.toString())
        with(DensityAmbient.current) {
            Container( modifier = LayoutWidth.Constrain(200.ipx.toDp(), 300.ipx.toDp())) {
                    WithConstraints { constraints2 ->
                        Log.d("Constraints2", constraints2.toString())
                        Column() {
                            Text("Test1")
                            Text("Test2")
                        }
                    }
                }
            }
        }

The log:

D/Constraints: Constraints(minWidth=0.ipx, maxWidth=800.ipx, minHeight=0.ipx, maxHeight=1173.ipx)

D/Constraints2: Constraints(minWidth=0.ipx, maxWidth=300.ipx, minHeight=0.ipx, maxHeight=1173.ipx)

I think that means Container lets its children be as small as they want, even when the container itself will be min width 200.

You are absolutely right Container source:

val childConstraints = containerConstraints

.copy(minWidth = 0.ipx, minHeight = 0.ipx)

.offset(-totalHorizontal, -totalVertical)