Add if statement to avoid UnboundLocalError

[ppaslan]

When there are no challenges installed in ctfd, sync will throw an UnboundLocalError because the variable 'c' at line 209 will be unreferenced.
This adds a simple sanity check to avoid running sync at all if there are no challenges installed.

[ColdHeat]

Can you provide a copy of the exception you get? If there are no challenges then wouldn't it be an empty list and then c would just not go into the for loop?

[ppaslan]

Can you provide a copy of the exception you get? If there are no challenges then wouldn't it be an empty list and then c would just not go into the for loop?

Of course, and i checked, it is indeed and empty list, however i think that the variable c gets unreferenced because of this.

ctf@localhost:~/challenges$ ctf challenge sync gift_bag/
Found gift_bag/challenge.yml
Loaded Gift Bag
Traceback (most recent call last):
  File "/usr/local/bin/ctf", line 8, in <module>
    sys.exit(main())
  File "/usr/local/lib/python3.8/dist-packages/ctfcli/__main__.py", line 107, in main
    fire.Fire(CTFCLI)
  File "/usr/local/lib/python3.8/dist-packages/fire/core.py", line 138, in Fire
    component_trace = _Fire(component, args, parsed_flag_args, context, name)
  File "/usr/local/lib/python3.8/dist-packages/fire/core.py", line 466, in _Fire
    component, remaining_args = _CallAndUpdateTrace(
  File "/usr/local/lib/python3.8/dist-packages/fire/core.py", line 675, in _CallAndUpdateTrace
    component = fn(*varargs, **kwargs)
  File "/usr/local/lib/python3.8/dist-packages/ctfcli/cli/challenges.py", line 199, in sync
    f'Couldn\'t find existing challenge {c["name"]}. Perhaps you meant install instead of sync?',
UnboundLocalError: local variable 'c' referenced before assignment

[ColdHeat]

Ah okay I see now. The issue is that instead of c["name"] it should actually be challenge["name"]!

Do you think you can test that out and update your PR if it does fix it?

[ppaslan]

Ah okay I see now. The issue is that instead of c["name"] it should actually be challenge["name"]!

Do you think you can test that out and update your PR if it does fix it?

There we go :)

[ColdHeat]

Thanks!