I am trying to increase the Voting period in OZ governor contract, by creating a proposal and then executing it. And I am doing this via Tally, which allows to simulate a proposal before creating, and when I ran the simulation, it failed.
The simulation fails because what you simulate is a call to setVotingPeriod that targets the governor. The simulation is missing the part in execute() that whitelists the operation before executing it.
This is a protection that is usefull when the executor is a third party, that may execute call that do not originate for the governor.