Contracts in substrate 3.0

Question

A customer has a substrate blockchain based on Tag 3.0.0 It uses pallet-contracts = { git = "https://github.com/paritytech/substrate.git", tag = "v3.0.0" }

The problem is that when I compile a smart contract with cargo contract and try to upload it (it uses the old-ui, see image below), it complains that the ABI is invalid.

'''Invalid ABI file — Error: Invalid JSON ABI structure supplied, expected a recent metadata version'''

It works Ok with the last version of substrate from the repo.

So my questions are: .- Is it possible for cargo contract build contracts compatible with 3.0.0? .- Is it possible to upgrade just the contract pallet on a substrate based on 3.0.0?

Thanks very much. Regads; Fernando

Answer 1

Is it possible to upgrade just the contract pallet on a substrate based on 3.0.0?

Yes, this is definitely possible! Substrate enables forkless runtime upgrades. This tutorial here walks through the steps of upgrading Substrate. Just be cautious when doing this and ensure the pallet_contracts is configured correctly for the new version. I recommend comparing the current substrate-contracts-node with your Substrate node and adding any differences relating to pallet_contracts. Note: The substrate-contracts-node uses instant block sealing, so make sure not to edit your node's consensus when comparing.

Is it possible for cargo contract build contracts compatible with 3.0.0?

Yes, it is also possible to use a cargo-contract version that is compatible with ink! v3.0.0. To do this, you will likely need to downgrade cargo-contract. However, it is recommended to use the newest release of ink! (upgrade pallet_contracts, see above).

See here for cargo-contract releases.

For example, to downgrade:

cargo install cargo-contract --version 1.4.0 --force