FRR Router binary path /usr/local/sbin does not contain daemons

[UnicornJin]

Hi! I found when I try to initialize a Router like:

net.addRouter('r1')

There will be error like:

*** Starting 1 routers
r1
Traceback (most recent call last):
File "/home//p4-utils/test.py", line 37, in
net.startNetwork()
File "/home//p4-utils/p4utils/mininetlib/network_API.py", line 1119, in startNetwork
self.net.start()
File "/home//p4-utils/p4utils/mininetlib/net.py", line 134, in start
router.start()
File "/home//p4-utils/p4utils/mininetlib/node.py", line 458, in start
raise FileNotFoundError(
FileNotFoundError: binary path /usr/local/sbin does not contain daemons!

Any idea why this happen?