TrackPayment got error for payment, Found nil circuit

[microlancer]

Any ideas why this is giving an error? It seems like the transaction settled, but there's an error at the end.

2025-05-07 04:38:29.964 [INF] GRPH: Processed channels=0 updates=140 nodes=2 in last 59.996731219s
2025-05-07 04:38:44.017 [DBG] HSWC: ChannelLink(152ea2674fcfce34a0fc19d69ebb01c482afd691f0d96f1ac3dad655159ff4ce:1): queueing keystone of ADD open circuit: (Chan ID=0:0:0, HTLC ID=482323)->(Chan ID=803188:1618:1, HTLC ID=24298)
2025-05-07 04:38:44.026 [DBG] HSWC: Subscribing to result for attemptID=482323
2025-05-07 04:38:44.084 [DBG] HSWC: ChannelLink(152ea2674fcfce34a0fc19d69ebb01c482afd691f0d96f1ac3dad655159ff4ce:1): removing Add packet (Chan ID=0:0:0, HTLC ID=482323) from mailbox
2025-05-07 04:38:45.256 [DBG] HSWC: Closed completed SETTLE circuit for 76eb3163f656a0b6bb324f5f9f4f63f32139902d2c7f5b6c109f2f71f406657c: (0:0:0, 482323) <-> (803188:1618:1, 24298)
2025-05-07 04:38:45.257 [DBG] HSWC: Storing result for attemptID=482323
2025-05-07 04:38:45.261 [DBG] HSWC: Tearing down circuit with SETTLE pkt, removing circuit=(Chan ID=0:0:0, HTLC ID=482323) with keystone=(Chan ID=803188:1618:1, HTLC ID=24298)
2025-05-07 04:38:45.268 [INF] SRVR: Adding preimage=97c0b7fbbf304cb48a6e37df0d5c7f7a1f0e97e19f6e90a7ae52026524c080a1 to witness cache for 76eb3163f656a0b6bb324f5f9f4f63f32139902d2c7f5b6c109f2f71f406657c
2025-05-07 04:38:45.268 [DBG] HSWC: Received network result *lnwire.UpdateFulfillHTLC for attemptID=482323
2025-05-07 04:38:45.280 [DBG] HSWC: Closed SETTLE circuit for 76eb3163f656a0b6bb324f5f9f4f63f32139902d2c7f5b6c109f2f71f406657c: (0:0:0, 482323) <-> (803188:1618:1, 24298)
2025-05-07 04:38:45.306 [DBG] RRPC: TrackPayment called for payment 76eb3163f656a0b6bb324f5f9f4f63f32139902d2c7f5b6c109f2f71f406657c
2025-05-07 04:38:45.313 [ERR] RRPC: TrackPayment got error for payment 76eb3163f656a0b6bb324f5f9f4f63f32139902d2c7f5b6c109f2f71f406657c: <nil>
2025-05-07 04:38:45.551 [DBG] HSWC: ChannelLink(152ea2674fcfce34a0fc19d69ebb01c482afd691f0d96f1ac3dad655159ff4ce:1): settle-fail-filter: count=1, filter=[0]
2025-05-07 04:38:45.553 [DBG] HSWC: Found nil circuit: packet=(*htlcswitch.htlcPacket)(0xc008cfb440)({
 incomingChanID: (lnwire.ShortChannelID) 0:0:0,
 outgoingChanID: (lnwire.ShortChannelID) 803188:1618:1,
 incomingHTLCID: (uint64) 0,
 outgoingHTLCID: (uint64) 24298,
 sourceRef: (*channeldb.AddRef)(<nil>),
 destRef: (*channeldb.SettleFailRef)(0xc0175c0d80)({
  Source: (lnwire.ShortChannelID) 803188:1618:1,
  Height: (uint64) 239374,
  Index: (uint16) 0
 }),
 incomingAmount: (lnwire.MilliSatoshi) 0 mSAT,
 amount: (lnwire.MilliSatoshi) 0 mSAT,
 htlc: (*lnwire.UpdateFulfillHTLC)(0xc010698b60)({
  ChanID: (lnwire.ChannelID) (len=32 cap=32) cef49f1555d6dac31a6fd9f091d6af82c401bb9ed619fca034cecf4f67a22e14,
  ID: (uint64) 24298,
  PaymentPreimage: ([32]uint8) (len=32 cap=32) {
   00000000  97 c0 b7 fb bf 30 4c b4  8a 6e 37 df 0d 5c 7f 7a  |.....0L..n7..\.z|
   00000010  1f 0e 97 e1 9f 6e 90 a7  ae 52 02 65 24 c0 80 a1  |.....n...R.e$...|
  },
  CustomRecords: (lnwire.CustomRecords) <nil>,
  ExtraData: (lnwire.ExtraOpaqueData) <nil>
 }),
 obfuscator: (hop.ErrorEncrypter) <nil>,
 localFailure: (bool) false,
 linkFailure: (*htlcswitch.LinkError)(<nil>),
 convertedError: (bool) false,
 hasSource: (bool) false,
 isResolution: (bool) false,
 circuit: (*htlcswitch.PaymentCircuit)(<nil>),
 incomingTimeout: (uint32) 0,
 outgoingTimeout: (uint32) 0,
 inOnionCustomRecords: (record.CustomSet) <nil>,
 inWireCustomRecords: (lnwire.CustomRecords) <nil>,
 originalOutgoingChanID: (lnwire.ShortChannelID) 0:0:0,
 inboundFee: (models.InboundFee) {
  Base: (int32) 0,
  Rate: (int32) 0
 }
})

2025-05-07 04:38:53.659 [DBG] HLCK: Health check: chain backend invoking success callback
2025-05-07 04:38:54.288 [DBG] HSWC: Sent 2 satoshis and received 0 satoshis in the last 10 seconds (0.200000 tx/sec)
2025-05-07 04:39:29.966 [INF] GRPH: Processed channels=0 updates=87 nodes=50 in last 59.998323075s

"version":  "0.18.5-beta commit=v0.18.5-beta",
"commit_hash":  "4ccf4fc24c750d098cf24566ef4bbc0311c7d476",

bitcoind 27.1

[hieblmi]

Thanks for reporting. The TrackPayment got error for payment seems to be a faulty logline that was fixed in the latest version:
old:

// trackPayment writes payment status updates to the provided stream.
func (s *Server) trackPayment(subscription routing.ControlTowerSubscriber,
	identifier lntypes.Hash, stream Router_TrackPaymentV2Server,
	noInflightUpdates bool) error {

	err := s.trackPaymentStream(
		stream.Context(), subscription, noInflightUpdates, stream.Send,
	)

	// If the context is canceled, we don't return an error.
	if errors.Is(err, context.Canceled) {
		log.Infof("Payment stream %v canceled", identifier)

		return nil
	}

	// Otherwise, we will log and return the error as the stream has
	// received an error from the payment lifecycle.
	log.Errorf("TrackPayment got error for payment %v: %v", identifier, err)

	return err
}

new:

func (s *Server) trackPayment(subscription routing.ControlTowerSubscriber,
	identifier lntypes.Hash, stream Router_TrackPaymentV2Server,
	noInflightUpdates bool) error {

	err := s.trackPaymentStream(
		stream.Context(), subscription, noInflightUpdates, stream.Send,
	)
	switch {
	case err == nil:
		return nil

	// If the context is canceled, we don't return an error.
	case errors.Is(err, context.Canceled):
		log.Infof("Payment stream %v canceled", identifier)

		return nil

	default:
	}

	// Otherwise, we will log and return the error as the stream has
	// received an error from the payment lifecycle.
	log.Errorf("TrackPayment got error for payment %v: %v", identifier, err)

	return err
}

So this should be handled.

The Found nil circuit is because one of the following, but unsure exactly why:

// Circuit was previously closed, but has not been deleted.
// We'll just drop this response until the circuit has been
// fully removed.
case ErrCircuitClosing:
	return nil, err

// Failed to close circuit because it does not exist. This is
// likely because the circuit was already successfully closed.
// Since this packet failed locally, there is no forwarding
// package entry to acknowledge.
case ErrUnknownCircuit:
	return nil, err

// Unexpected error.
default:
	return nil, err

[microlancer]

Thank you, I'll see how it goes on the new version when it is released.