rpc: try to catch EOF error from lnd sendpayment

[Roasbeef]

A user observed that when using Python, they get an EOF even if the payment succeeds. My guess is that lnd has hung up, then we try to recv and get an EOF error. With this PR, we try to catch that EOF error and just return nil.

One other idea: do we need to call CloseSend at the very end or in a defer?

Fixes: #1216

[coveralls]

Pull Request Test Coverage Report for Build 12038637695

Details

• 0 of 6 (0.0%) changed or added relevant lines in 1 file are covered.
• 32 unchanged lines in 6 files lost coverage.
• Overall coverage decreased (-0.001%) to 40.846%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
rpcserver.go	0	6	0.0%

Files with Coverage Reduction	New Missed Lines	%
tapchannel/aux_leaf_signer.go	3	36.31%
asset/mock.go	3	92.2%
tapgarden/caretaker.go	4	68.5%
rpcserver.go	6	0.0%
asset/asset.go	6	80.96%
universe/interface.go	10	52.81%

Totals
Change from base Build 12038519798:	-0.001%
Covered Lines:	25714
Relevant Lines:	62954

---

💛 - Coveralls

[ZZiigguurraatt]

Not sure if I'm doing something wrong, but I'm getting this error.

unknown flag `taproot-assets.experimental.rfq.priceoracleaddress'
could not load config: error parsing flags: unknown flag `taproot-assets.experimental.rfq.priceoracleaddress'

[ZZiigguurraatt]

Has taproot-assets.experimental.rfq.priceoracleaddress been depreciated for something else?

[guggero]

Are you running tapd directly? Then you need to remove the taproot-assets prefix as that's only valid in litd.

[ZZiigguurraatt]

I'm running litd. I didn't think you could use sendpayment with tapd directly.

[guggero]

you could use sendpayment with tapd directly

Yeah, you can't. Just trying to find out what's wrong here... Is it possible you have an old litd somewhere in your $PATH that's being picked up?
The flag still exists on the update-to-lnd-18-4 branch (but it probably doesn't on master):

litd --help | grep oracle
      --taproot-assets.experimental.rfq.priceoracleaddress=                    Price oracle gRPC server address (rfqrpc://<hostname>:<port>). To use the
                                                                               use_mock_price_oracle_service_promise_to_not_use_on_mainnet

[ZZiigguurraatt]

you could use sendpayment with tapd directly

Yeah, you can't. Just trying to find out what's wrong here... Is it possible you have an old litd somewhere in your $PATH that's being picked up? The flag still exists on the update-to-lnd-18-4 branch (but it probably doesn't on master):

litd --help | grep oracle
      --taproot-assets.experimental.rfq.priceoracleaddress=                    Price oracle gRPC server address (rfqrpc://<hostname>:<port>). To use the
                                                                               use_mock_price_oracle_service_promise_to_not_use_on_mainnet

I was running inside docker, so I don't think that was the issue.

[Roasbeef]

Updated the PR body with more context.

[ZZiigguurraatt]

Sorry, I accidentally was not using dev.Dockerfile, so it was just pulling from master instead of using my locally checked out branch.

I can confirm this fix works!

[guggero]

Thanks for the fix! LGTM 🎉

[guggero]

nit: Use errors.Is() instead? Though it shouldn't really be wrapped at this point, so doesn't matter too much.