def run2(self):
    # a reference to our map canvas
    canvas = iface.mapCanvas()

    # this QGIS tool emits as QgsPoint after each click on the map canvas
    pointTool = QgsMapToolEmitPoint(canvas)
    # Checkpoint
    print("S 1")
    pointTool.canvasClicked.connect( self.display_point )
    canvas.setMapTool( pointTool )
    # Checkpoint
    print("S 3")

def display_point( pointTool ):

    print('({:.4f}, {:.4f})'.format(pointTool[0], pointTool[1]))
    # Checkpoint
    print("S 2")