substrate forkless upgrade tutorial, pallet_scheduler has breaking changes

Question

I am following https://docs.substrate.io/tutorials/v3/forkless-upgrades/ and have added

pallet-scheduler = { default-features = false, git = "https://github.com/paritytech/substrate.git", branch = "polkadot-v0.9.19" } to my Cargo.toml.

It seems that this appears to be a newer version and requires me to specify NoPreimagePostponement and PreimageProvider in pallet_scheduler::Config.

Here is the exact error message: error[E0046]: not all trait items implemented, missing: PreimageProvider, NoPreimagePostponement

What should I set those value to be? https://docs.rs/pallet-scheduler/latest/pallet_scheduler/trait.Config.html doesn't seem to also have those properties and I'm guessing that the crate hasn't been published yet.

Answer 1

The associated pull request mentions the changes necessary. In short, just set the following to imitate the desired behavior:

type PreimageProvider = ();
type NoPreimagePostponement = ();