TypeError in practracker "includes.py" script

When practracker finds a forbidden include, it causes a Python TypeError. Example:

user@computer:~/tor$ make check-includes
python3 ./scripts/maint/practracker/includes.py .
Unusual pattern permitted.h in ./scripts/maint/practracker/testdata
Forbidden include of lib/lock/compat_mutex.h at ./src/lib/evloop/eventqueue.h:8
Traceback (most recent call last):
  File "./scripts/maint/practracker/includes.py", line 285, in <module>
    main(sys.argv)
  File "./scripts/maint/practracker/includes.py", line 282, in main
    list_advisories=args.list_advisories)
  File "./scripts/maint/practracker/includes.py", line 240, in run_check_includes
    files in its enclosing directory.""".format(RULES_FNAME))
TypeError: 'Error' object is not callable
make: *** [check-includes] Error 1

This seems to be caused by an err() function being removed from the code sometime in the past, but the call to err() was never also removed.