Error in tool_offsetview.py

    def set_current_view(self):
        self.makeCurrent()
        if self.current_view not in ['p', 'x', 'y', 'y2', 'z', 'z2']:
            return
        return getattr(self, 'set_view_%s' % self.current_view)()

    def select(self, x_view, y_view):
        if self.canon is None: return
        pmatrix = glGetDoublev(GL_PROJECTION_MATRIX)
        glMatrixMode(GL_PROJECTION)
        glPushMatrix()
        glLoadIdentity()
        vport = glGetIntegerv(GL_VIEWPORT)
        gluPickMatrix(x_view, vport[3]-y_view, 5, 5, vport)
        glMultMatrixd(pmatrix)
        glMatrixMode(GL_MODELVIEW)

        glSelectBuffer(self.select_buffer_size)
        glRenderMode(GL_SELECT)
        glInitNames()
        glPushName(0)

        if self.get_show_rapids():
            glCallList(self.dlist('select_rapids', gen=self.make_selection_list))
        glCallList(self.dlist('select_norapids', gen=self.make_selection_list))
        
        try:
            buffer = glRenderMode(GL_RENDER)
        except Exception as e:
            print(e)
            buffer = []

        if buffer:
            print('buffer')
            min_depth, max_depth, names = (buffer[0].near, buffer[0].far, buffer[0].names)
            for point in buffer:
                if min_depth < point.near:
                    min_depth, max_depth, names = (point.near, point.far, point.names)
            self.set_highlight_line(names[0])
        else:
            print('No buffer')
            self.set_highlight_line(None)

        glMatrixMode(GL_PROJECTION)
        glPopMatrix()
        glMatrixMode(GL_MODELVIEW)

    def select_fire(self):
        if self.inhibit_selection: return
        if STATUS.is_auto_running(): return
        if not self.select_primed: return
        x, y = self.select_primed
        self.select_primed = None
        self.makeCurrent()
        self.select(x, y)