Install Docker
Copy LND data directory from Zap to ./data
On Mac, the default is
~/Library/Application\ Support/Zap/lnd/bitcoin/mainnet/<zap-wallet-name>/data/
Build and start the Docker container
docker-compose build
docker-compose up -d
docker-compose exec lnd_btc bash
Once inside the container, get all invoices that are in an ACCEPTED state.
lncli --tlscertpath=/shared/lnd-tls-btc.cert --macaroonpath=/shared/lnd-admin-btc.macaroon listinvoices --pending_only | grep -i 'state'
Copy the r_hash of the invoice
Convert the r_hash from base64 to hex (see main.js for example)
Run
lncli --tlscertpath=/shared/lnd-tls-btc.cert --macaroonpath=/shared/lnd-admin-btc.macaroon cancelinvoice $r_hash
If the invoice was successfully cancelled, stdout will print {}
Stop the Docker container
docker-compose down
Backup channel.db in Zap directory (to channel.db.bak)
Copy channel.db from docker shared directory to Zap directory
Start Zap
Celebrate