cts中遇到的一个warning

梦想的东南

warning: clock network timing may not be up-to-date since only 62.144211 percentage of clock nets are routed (TIM-223)
cts后report_timing的时候一直有这个warning，man了一下显示：
DESCRIPTION
This message is issued when the previous command caused some of the clock nets to be broken, and therefore delays can no longer
be computed accurately using the clock Arnoldi flow.
WHAT NEXT
Reroute all the clocks and fix the broken nets before performing extraction and timing reporting.
我就有疑问：
1，cts后我还没做什么呢怎么会有clock nets的broken啊，是不是因为clock_opt的时候no_clock_route导致的啊？
2，这个需要重新cts解决吗？