Failed assertion: line 5342 pos 12: '!_dirty': is not true exceptions related to setState() being called during the build phase, as well as assertions indicating that some widget state is not in a clean state when it should be.

[jbarasa]

══╡ EXCEPTION CAUGHT BY FOUNDATION LIBRARY ╞════════════════════════════════════════════════════════
The following assertion was thrown while dispatching notifications for DateController:
setState() or markNeedsBuild() called during build.
This ListenableBuilder widget cannot be marked as needing to build because the framework is already
in the process of building widgets. A widget can be marked as needing to be built during the build
phase only if one of its ancestors is currently building. This exception is allowed because the
framework builds parent widgets before children, which means a dirty descendant will always be
built. Otherwise, the framework might not visit this widget during this build phase.
The widget on which setState() or markNeedsBuild() was called was:
ListenableBuilder
The widget which was currently being built when the offending call was made was:
ListenableBuilder