MainWindow::MainWindow(QWidget *parent) :
  QMainWindow(parent)
{
  QWebView *test_view = new QWebView(this);
  QWebPage *page = test_view->page();
}

This is the minimal code needed to crash the program in release mode. Debug version works fine, release version crashes on the test_view->page() call. Attaching the project used to reproduce this issue.