Error generating compact proof

[liamaharon]

Reported here https://substrate.stackexchange.com/questions/10351/try-runtime-failed-to-generate-compact-proof-trieerrorinvalidstateroot and also impacts Asset Hub Kusama main branch.

Calling into https://github.com/paritytech/polkadot-sdk/blob/4ca193f88b55dc9b12d7a586113f9db192e1bdd8/substrate/primitives/trie/src/storage_proof.rs#L103 when calculating the PoV can return an error when the runtime differs in a particular way relative to the runtime the snapshot was generated from.

To debug, can bisect the Fellowship Runtime repo commit history starting from v1.0.1 to see exactly which change caused this issue.

[liamaharon]

Simply an error when the PoV is empty e.g. due to Migrations tuple being empty.