Lightning: "Cannot afford transaction"

[Fonta1n3]

Issue and Steps to Reproduce

Trying to spend 20,000 sats to fund a channel but getting "Cannot afford transaction" error. I have about 8 million sats so not sure why im getting the error?

listfunds output:
"outputs": [ { "txid": "c9f6a28f7af2da6da66f9a4c6b1404037a3100553bd6dd53a3d8e56920fe81e9", "output": 1, "value": 7647454, "amount_msat": "7647454000msat", "address": "tb1qa8c6j0lu02ur9u4g673m33ume247wy29q70snz", "status": "unconfirmed" }, { "txid": "845b1aa450d016f4360ae067f399e60cfff22ef417e059a6b9bbf15c89292bb1", "output": 1, "value": 978846, "amount_msat": "978846000msat", "address": "tb1qct9k6dzlxqkn0242uleyndtm8tyfztax2qt253", "status": "unconfirmed" } ], "channels": [ { "peer_id": "030f0bf260acdbd3edcad84d7588ec7c5df4711e87e6a23016f989b8d3a4147230", "channel_sat": 20000, "our_amount_msat": "20000000msat", "channel_total_sat": 20000, "amount_msat": "20000000msat", "funding_txid": "c9f6a28f7af2da6da66f9a4c6b1404037a3100553bd6dd53a3d8e56920fe81e9" }, { "peer_id": "036b96e4713c5f84dcb8030592e1bd42a2d9a43d91fa2e535b9bfd05f2c5def9b9", "channel_sat": 20000, "our_amount_msat": "20000000msat", "channel_total_sat": 20000, "amount_msat": "20000000msat", "funding_txid": "845b1aa450d016f4360ae067f399e60cfff22ef417e059a6b9bbf15c89292bb1" } ] }

[billygarrison]

I've been getting this error too the past couple days. I'm on 0.7.0.

Tried to fund a handful of different channels with ~ 400k sats each and at least two of them gave that error. I also had millions of sats to spare.

Couple things that were different that could have contributed to the problem are that I use feerate=slow, for at least one of the channels I had one or more opening transactions waiting in the mempool.

I waited 30-60 minutes and when I tried again, I was able to open the channels.

[niftynei]

@FontaineDenton your listfund outputs are currently unconfirmed

"status": "unconfirmed"

[billygarrison]

Ah, that would explain my situation as well!

for at least one of the channels I had one or more opening transactions waiting in the mempool
I waited 30-60 minutes and when I tried again, I was able to open the channels.

I had enough funds but had to wait for the change UTXOs from my channel opening transactions to confirm.

Thanks @niftynei!

[Fonta1n3]

@niftynei That would explain it but I funded the other channels with the unconfirmed status. You can see the proof of that by checking the tx id in a block explorer and cross referencing the addresses.

[cdecker]

I just noticed that I didn't add the optional minconf argument to fundchannel, that'd allow you to use unconfirmed outputs to fund a new channel (at the risk of chaining channel fundings which usually end up being nasty).

Would changing the message to Insufficient confirmed funds to fund channel be better?

[Fonta1n3]

Wow I found a real bug! That would be better. Just from a UX pov i didn't look at whether the onchain tx had confirmed or not as the other fundchannels were successful, better to make it obvious you have to wait for confs.