Building topology in P4 program

Hello, I’m sorry to bother you so late. I have a question here that involves building a topology. In the p4-utils environment, I set up a topology according to the method mentioned in p4-learning, but I encountered the following problem. May I ask what caused this problem

Reading JSON configuration file…
“l3” assignment strategy selected.
Traceback (most recent call last):
File “/usr/local/bin/p4run”, line 11, in
load_entry_point(‘p4utils’, ‘console_scripts’, ‘p4run’)()
File “/home/p4/p4-tools/p4-utils/p4utils/”, line 739, in main
File “/home/p4/p4-tools/p4-utils/p4utils/”, line 341, in init
File “/home/p4/p4-tools/p4-utils/p4utils/mininetlib/”, line 2650, in l3
assert not self.is_multigraph()

It seems much more likely that someone might be able to diagnose the problem if you published the contents of any relevant input files, rather than just the error message, e.g. the contents of file clos_four_switches_1.json

One good option for doing so is to put the files into a public repository, e.g. on (but other sites are fine, too), and put a link to those files in a question on this forum.