In msg 7663 on issue 2551195 Ralf reported:

    Note that the yaml output of schema-dump.py was already broken, it tries
    to split a string on '<' assigning the result to a 2-tuple resulting in
    a ValueError. May very well be that this works with the standard schema, though.

I tested this against two server, one a demo (with csrf protection) and the other
an enhanced tracker. I can't reproduce the error.

I updated the script to set csrf protection headers and will see if Ralf can reproduce.
It may be his tracker only. If so, close this as not reproducible.