How to use `AccountIndex` with `MultiAddress` in a parachain?

Question

In this pull request #19 I am trying to merge the following features into a working parachain based on the substrate-parachain-template in this pull request #17 here:

• Added AccountIndex to the address here so it became the following. Previously it was MultiAddress<AccountId, ()>;)

pub type Address = MultiAddress<AccountId, AccountIndex>;

• Added CreateSignedTransaction here. Its purpose is described in this answer
• Added SigningTypes here
• Used SendTransactionTypes here

But it generates the errors shown here.

However, there weren't any errors when I previously made the same changes in the standalone chain based on the substrate-node-template (a separate repository) in this pull request #215.

What steps could be taken to try to fix the errors?

How would you satisfying all the unsatisfied trait bounds so the functions execute_block, initialize_block, apply_extrinsic, finalize_block, validate_transaction, offchain_worker may be called?

How would you make struct UncheckedExtrinsic satisfy trait Checkable<ChainContext<Runtime>>?

How would you implement trait Checkable<ChainContext<Runtime>> for trait bound UncheckedExtrinsic<MultiAddress<sp_runtime::AccountId32, u32>... in register_validate_block, which is required by bound validate_block?

Where is the implementation for UncheckedExtrinsic<Address, Call, Signature, Extra> as Checkable<Lookup>> that it says it found?

Update 15th March: I don't think the changes in pull request #19 are necessary, because Kilt's Spiritnet parachain codebase here that has already live also uses dependencies from Substrate branch 'polkadot-v0.9.17', but even though they are using pallets like pallet_indices, they haven't added AccountIndex to MultiAddress, and they aren't using CreateSignedTransaction, SigningTypes, or SendTransactionTypes. Similarly with the live Zeitgeist parachain codebase here isn't using it either.

Answer 1

In your frame_system::Config this line :

    type Lookup = AccountIdLookup<AccountId, ()>;

needs to say

    type Lookup = AccountIdLookup<AccountId, AccountIndex>;

This should probably fix your issue.