track: CLN misidentifies channels as being unavailable

[cdecker]

@roeierez reports that a payment went wrong, despite the channels being up and running.

Timeline

• 2024-04-17T10:24:15+02:00 schedule called
• 2024-04-17T10:24:19+02:00 Node startup complete
• 2024-04-17T10:24:23+02:00 Signer 0 attaches, initiating reconnect (datastore returns the correct IP address for the Diem LSP iirc)
• 2024-04-17T10:24:27+02:00 Peer reconnected and re-established
• 2024-04-17T10:25:55+02:00 Blocksync complete
• 2024-04-17T10:31:25+02:00 Call to pay, all preconditions are fulfilled, should go through
• 2024-04-17T10:32:00+02:00 We don't have any channels

That last line is strange, because we checked before that there are indeed channels available, sounds like CLN is not recognizing its channel there.

node_id: 02641966fa87401c584f41abc2b598e6687a5629642b18775e1b147caa023eb731

[cdecker]

Checking with the pay source-code we can see that the warning is logged here

https://github.com/ElementsProject/lightning/blob/c4edec8e223dddaab08397d60270bd805cc582e2/plugins/libplugin-pay.c#L893-L900

What this means is that our local gossip does not know about our local channels, and we are missing private gossip. This can have a number of reasons, that we need to investigate.