I tried to use the Sleepless Labour power on my agent performing the challenge "Wrestle for control of Primal Font". It returns the error message:

"INVALID: Must target an agent performing a challenge (cannot be used on non-stat based challenges such as resting, challenges of indefinite length or channeled spells such as magic.) Agent must have > 2 HP."

I assume this is a bug as:
* I am targetting an agent performing a challenge.
* "Wrestle for control of Primal Font" is a stat-based challenge. (it uses all four stats).
* The challenge has a definite length (complexity is 100).
* The challenge is not channelled magic.
* The agent has more than 2 HP.