[encointer] Barrier error for unpaid superuser XCM `authorizeUpgrade` from relay

[brenzi]

In order to test the upcoming 1.2 release for Encointer, we upgraded Encointer on rococo to commit 35048df which worked well. Then, to test new storage migrations, we wanted to test a newer commit 503e481 but executing XCM failed there.

As we almost copy-pasted the Barrier setting from asset hub, this could be relevant for other system chains too.

runtimes/system-parachains/encointer/src/xcm_config.rs

Lines 121 to 145 in 360581f

	pub type Barrier = TrailingSetTopicAsId<
	DenyThenTry<
	DenyReserveTransferToRelayChain,
	(
	TakeWeightCredit,
	// Expected responses are OK.
	AllowKnownQueryResponses<PolkadotXcm>,
	// Allow XCMs with some computed origins to pass through.
	WithComputedOrigin<
	(
	// If the message is one that immediately attempts to pay for execution, then
	// allow it.
	AllowTopLevelPaidExecutionFrom<Everything>,
	// Parent, its pluralities (i.e. governance bodies), parent's treasury and
	// sibling bridge hub get free execution.
	AllowExplicitUnpaidExecutionFrom<(ParentOrParentsPlurality,)>,
	// Subscriptions for version tracking are OK.
	AllowSubscriptionsFrom<ParentRelayOrSiblingParachains>,
	),
	UniversalLocation,
	ConstU32<8>,
	>,
	),
	>,
	>;

We tried sending XCMv3 and XCMv4. Here's the send authorizeUpgrade call for XCM V4

Apply that with chopsticks

npx @acala-network/chopsticks@latest xcm -r=configs/rococo.yml -p=configs/encointer-rococo.yml

Yields messageQueue.ProcessingFailed: Unsupported

xcm::weight                  TRACE: FixedWeightBounds message: Xcm([Transact { origin_kind: Superuser, require_weight_at_most: Weight { ref_time: 4000000, proof_size: 100 }, call: "0x01025254b692414f6cd14dc96353eb1323beef8538373eccc268c390357e22b04b7d00" }, SetTopic([6, 124, 134, 201, 16, 109, 26, 229, 183, 186, 118, 102, 38, 5, 192, 211, 203, 208, 105, 70, 83, 156, 31, 107, 164, 28, 189, 2, 22, 126, 70, 33])])
xcm::execute                 TRACE: origin: Location { parents: 1, interior: Here }, message: Xcm([Transact { origin_kind: Superuser, require_weight_at_most: Weight { ref_time: 4000000, proof_size: 100 }, call: "0x01025254b692414f6cd14dc96353eb1323beef8538373eccc268c390357e22b04b7d00" }, SetTopic([6, 124, 134, 201, 16, 109, 26, 229, 183, 186, 118, 102, 38, 5, 192, 211, 203, 208, 105, 70, 83, 156, 31, 107, 164, 28, 189, 2, 22, 126, 70, 33])]), weight_credit: Weight { ref_time: 0, proof_size: 0 }
xcm::barriers                TRACE: TrailingSetTopicAsId origin: Location { parents: 1, interior: Here }, instructions: [Transact { origin_kind: Superuser, require_weight_at_most: Weight { ref_time: 4000000, proof_size: 100 }, call: "0x01025254b692414f6cd14dc96353eb1323beef8538373eccc268c390357e22b04b7d00" }, SetTopic([6, 124, 134, 201, 16, 109, 26, 229, 183, 186, 118, 102, 38, 5, 192, 211, 203, 208, 105, 70, 83, 156, 31, 107, 164, 28, 189, 2, 22, 126, 70, 33])], max_weight: Weight { ref_time: 2004000000, proof_size: 100 }, properties: Properties { weight_credit: Weight { ref_time: 0, proof_size: 0 }, message_id: None }
xcm::barriers                TRACE: TakeWeightCredit origin: Location { parents: 1, interior: Here }, instructions: [Transact { origin_kind: Superuser, require_weight_at_most: Weight { ref_time: 4000000, proof_size: 100 }, call: "0x01025254b692414f6cd14dc96353eb1323beef8538373eccc268c390357e22b04b7d00" }], max_weight: Weight { ref_time: 2004000000, proof_size: 100 }, properties: Properties { weight_credit: Weight { ref_time: 0, proof_size: 0 }, message_id: Some([6, 124, 134, 201, 16, 109, 26, 229, 183, 186, 118, 102, 38, 5, 192, 211, 203, 208, 105, 70, 83, 156, 31, 107, 164, 28, 189, 2, 22, 126, 70, 33]) }
xcm::barriers                TRACE: AllowKnownQueryResponses origin: Location { parents: 1, interior: Here }, instructions: [Transact { origin_kind: Superuser, require_weight_at_most: Weight { ref_time: 4000000, proof_size: 100 }, call: "0x01025254b692414f6cd14dc96353eb1323beef8538373eccc268c390357e22b04b7d00" }], max_weight: Weight { ref_time: 2004000000, proof_size: 100 }, properties: Properties { weight_credit: Weight { ref_time: 0, proof_size: 0 }, message_id: Some([6, 124, 134, 201, 16, 109, 26, 229, 183, 186, 118, 102, 38, 5, 192, 211, 203, 208, 105, 70, 83, 156, 31, 107, 164, 28, 189, 2, 22, 126, 70, 33]) }
xcm::barriers                TRACE: WithComputedOrigin origin: Location { parents: 1, interior: Here }, instructions: [Transact { origin_kind: Superuser, require_weight_at_most: Weight { ref_time: 4000000, proof_size: 100 }, call: "0x01025254b692414f6cd14dc96353eb1323beef8538373eccc268c390357e22b04b7d00" }], max_weight: Weight { ref_time: 2004000000, proof_size: 100 }, properties: Properties { weight_credit: Weight { ref_time: 0, proof_size: 0 }, message_id: Some([6, 124, 134, 201, 16, 109, 26, 229, 183, 186, 118, 102, 38, 5, 192, 211, 203, 208, 105, 70, 83, 156, 31, 107, 164, 28, 189, 2, 22, 126, 70, 33]) }
xcm::barriers                TRACE: AllowTopLevelPaidExecutionFrom origin: Location { parents: 1, interior: Here }, instructions: [Transact { origin_kind: Superuser, require_weight_at_most: Weight { ref_time: 4000000, proof_size: 100 }, call: "0x01025254b692414f6cd14dc96353eb1323beef8538373eccc268c390357e22b04b7d00" }], max_weight: Weight { ref_time: 2004000000, proof_size: 100 }, properties: Properties { weight_credit: Weight { ref_time: 0, proof_size: 0 }, message_id: Some([6, 124, 134, 201, 16, 109, 26, 229, 183, 186, 118, 102, 38, 5, 192, 211, 203, 208, 105, 70, 83, 156, 31, 107, 164, 28, 189, 2, 22, 126, 70, 33]) }
xcm::barriers                TRACE: AllowExplicitUnpaidExecutionFrom origin: Location { parents: 1, interior: Here }, instructions: [Transact { origin_kind: Superuser, require_weight_at_most: Weight { ref_time: 4000000, proof_size: 100 }, call: "0x01025254b692414f6cd14dc96353eb1323beef8538373eccc268c390357e22b04b7d00" }], max_weight: Weight { ref_time: 2004000000, proof_size: 100 }, properties: Properties { weight_credit: Weight { ref_time: 0, proof_size: 0 }, message_id: Some([6, 124, 134, 201, 16, 109, 26, 229, 183, 186, 118, 102, 38, 5, 192, 211, 203, 208, 105, 70, 83, 156, 31, 107, 164, 28, 189, 2, 22, 126, 70, 33]) }
xcm::barriers                TRACE: AllowSubscriptionsFrom origin: Location { parents: 1, interior: Here }, instructions: [Transact { origin_kind: Superuser, require_weight_at_most: Weight { ref_time: 4000000, proof_size: 100 }, call: "0x01025254b692414f6cd14dc96353eb1323beef8538373eccc268c390357e22b04b7d00" }], max_weight: Weight { ref_time: 2004000000, proof_size: 100 }, properties: Properties { weight_credit: Weight { ref_time: 0, proof_size: 0 }, message_id: Some([6, 124, 134, 201, 16, 109, 26, 229, 183, 186, 118, 102, 38, 5, 192, 211, 203, 208, 105, 70, 83, 156, 31, 107, 164, 28, 189, 2, 22, 126, 70, 33]) }
xcm::should_execute          TRACE: did not pass barrier: origin: Location { parents: 1, interior: Here }, instructions: [Transact { origin_kind: Superuser, require_weight_at_most: Weight { ref_time: 4000000, proof_size: 100 }, call: "0x01025254b692414f6cd14dc96353eb1323beef8538373eccc268c390357e22b04b7d00" }], max_weight: Weight { ref_time: 2004000000, proof_size: 100 }, properties: Properties { weight_credit: Weight { ref_time: 0, proof_size: 0 }, message_id: Some([6, 124, 134, 201, 16, 109, 26, 229, 183, 186, 118, 102, 38, 5, 192, 211, 203, 208, 105, 70, 83, 156, 31, 107, 164, 28, 189, 2, 22, 126, 70, 33]) }
xcm::should_execute          TRACE: did not pass barrier: origin: Location { parents: 1, interior: Here }, instructions: [Transact { origin_kind: Superuser, require_weight_at_most: Weight { ref_time: 4000000, proof_size: 100 }, call: "0x01025254b692414f6cd14dc96353eb1323beef8538373eccc268c390357e22b04b7d00" }], max_weight: Weight { ref_time: 2004000000, proof_size: 100 }, properties: Properties { weight_credit: Weight { ref_time: 0, proof_size: 0 }, message_id: Some([6, 124, 134, 201, 16, 109, 26, 229, 183, 186, 118, 102, 38, 5, 192, 211, 203, 208, 105, 70, 83, 156, 31, 107, 164, 28, 189, 2, 22, 126, 70, 33]) }
xcm::execute                 TRACE: Barrier blocked execution! Error: <wasm:stripped>. (origin: Location { parents: 1, interior: Here }, message: Xcm([Transact { origin_kind: Superuser, require_weight_at_most: Weight { ref_time: 4000000, proof_size: 100 }, call: "0x01025254b692414f6cd14dc96353eb1323beef8538373eccc268c390357e22b04b7d00" }, SetTopic([6, 124, 134, 201, 16, 109, 26, 229, 183, 186, 118, 102, 38, 5, 192, 211, 203, 208, 105, 70, 83, 156, 31, 107, 164, 28, 189, 2, 22, 126, 70, 33])]), properties: Properties { weight_credit: Weight { ref_time: 0, proof_size: 0 }, message_id: Some([6, 124, 134, 201, 16, 109, 26, 229, 183, 186, 118, 102, 38, 5, 192, 211, 203, 208, 105, 70, 83, 156, 31, 107, 164, 28, 189, 2, 22, 126, 70, 33]) })

[franciscoaguirre]

The relevant barrier there is AllowExplicitUnpaidExecution.
You need to add an UnpaidExecution instruction at the top of your XCM.

[brenzi]

ah, will try. that wasn't necessary with XCMv3....

[brenzi]

confirmed. this call worked with chopsticks: 0xff00630003000100ad0f03082f000006020224f40091018c01025254b692414f6cd14dc96353eb1323beef8538373eccc268c390357e22b04b7d00

[franciscoaguirre]

It was changed in #187: ba359a4#diff-8d024174be6f061dbe75de6decc35492144955767ed71de9b979bb5933ea9918L132

[brenzi]

addendum. The next attempt failed because weights changed, too. The call which is expected to fix that is this