debugPrintBuildScope top-level property
Log all calls to BuildOwner.buildScope.
Combined with debugPrintRebuildDirtyWidgets or debugPrintBeginFrameBanner, this allows you to distinguish builds triggered by the initial mounting of a widget tree (e.g. in a call to runApp) from the regular builds triggered by the pipeline.
See also the discussion at WidgetsBinding.drawFrame.
bool debugPrintBuildScope = false