staking/election: prolonged era and emergency mode for governance submission.

bin/node/runtime/Cargo.toml

@@ -43,6 +43,7 @@ frame-benchmarking = { version = "3.1.0", default-features = false, path = "../.
 frame-support = { version = "3.0.0", default-features = false, path = "../../../frame/support" }
 frame-system = { version = "3.0.0", default-features = false, path = "../../../frame/system" }
 frame-system-benchmarking = { version = "3.0.0", default-features = false, path = "../../../frame/system/benchmarking", optional = true }
+frame-election-provider-support = { version = "3.0.0", default-features = false, path = "../../../frame/election-provider-support" }
 frame-system-rpc-runtime-api = { version = "3.0.0", default-features = false, path = "../../../frame/system/rpc/runtime-api/" }
 frame-try-runtime = { version = "0.9.0", default-features = false, path = "../../../frame/try-runtime", optional = true }
 pallet-assets = { version = "3.0.0", default-features = false, path = "../../../frame/assets" }

bin/node/runtime/src/lib.rs

@@ -480,6 +480,7 @@ parameter_types! {
 	pub OffchainRepeat: BlockNumber = 5;
 }
 
+use frame_election_provider_support::onchain;
 impl pallet_staking::Config for Runtime {
 	const MAX_NOMINATIONS: u32 = MAX_NOMINATIONS;
 	type Currency = Balances;
@@ -503,6 +504,8 @@ impl pallet_staking::Config for Runtime {
 	type NextNewSession = Session;
 	type MaxNominatorRewardedPerValidator = MaxNominatorRewardedPerValidator;
 	type ElectionProvider = ElectionProviderMultiPhase;
+	type GenesisElectionProvider =
+		onchain::OnChainSequentialPhragmen<pallet_election_provider_multi_phase::OnChainConfig<Self>>;
 	type WeightInfo = pallet_staking::weights::SubstrateWeight<Runtime>;
 }
 
@@ -513,7 +516,7 @@ parameter_types! {
 
 	// fallback: no need to do on-chain phragmen initially.
 	pub const Fallback: pallet_election_provider_multi_phase::FallbackStrategy =
-		pallet_election_provider_multi_phase::FallbackStrategy::OnChain;
+		pallet_election_provider_multi_phase::FallbackStrategy::Nothing;
 
 	pub SolutionImprovementThreshold: Perbill = Perbill::from_rational(1u32, 10_000);
 

frame/babe/src/mock.rs

@@ -213,6 +213,7 @@ impl pallet_staking::Config for Test {
 	type MaxNominatorRewardedPerValidator = MaxNominatorRewardedPerValidator;
 	type NextNewSession = Session;
 	type ElectionProvider = onchain::OnChainSequentialPhragmen<Self>;
+	type GenesisElectionProvider = Self::ElectionProvider;
 	type WeightInfo = ();
 }