Polkadot v0.9.2

Upgrade priority:❗ HIGH ❗ Please upgrade your node as soon as possible due to changes: Register ReadRuntimeVersionExt (#3045), ✅ audited Ensure election offchain workers don't overlap (paritytech/substrate#8828), ✅ trivial Embed runtime version as a custom section (paritytech/substrate#8688)

Native runtimes:

• Polkadot: 9020
• Kusama: 9020
• Westend: 9020

This release was tested against the following versions of rustc. Other versions may work.

• rustc 1.51.0 (2fd73fabe 2021-03-23)
• rustc 1.53.0-nightly (7f4afdf02 2021-04-22)

WASM runtimes built with srtool using rustc 1.52.0-nightly (d6eaea1c8 2021-03-14).

Proposal hashes:

• polkadot_runtime-v9020.compact.wasm - 0xd9e08dad1bc4e3c0703d5c5d82e1e319075eb82239d29f0dbc3a34e40e1e9218
• kusama_runtime-v9020.compact.wasm - 0xdad9387527ce6b7e0dfae5f279a7967d7cc263155e78fdc372f1b592ceca14c1

Changes

• Register ReadRuntimeVersionExt (#3045)

Client

• Make wasmtime the default when the feature is enabled (paritytech/substrate#8855)
• ✅ trivial Embed runtime version as a custom section (paritytech/substrate#8688)

Runtime

• ✅ not live Add Bridge Header Sync to Rococo Runtime (#2983)
• ✅ trivial Fix transaction payment fee/tip unbalanceds (paritytech/substrate#8860)
• ✅ audited Ensure election offchain workers don't overlap (paritytech/substrate#8828)
• ✅ not live contracts: Move Schedule from Storage to Config (paritytech/substrate#8773)
• ✅ audited Migrate pallet-offences to pallet attribute macro (paritytech/substrate#8763)
• ✅ trivial Migrate pallet-recovery to pallet attribute macro (paritytech/substrate#8761)
• ✅ trivial Embed runtime version as a custom section (paritytech/substrate#8688)
• ✅ audited Implement StorageNMap (paritytech/substrate#8635)