Rescan LND instructions

# Back-up the .lnd dir
`cp -r .lnd/ .lnd.old`
# copy the .lnd dir to another machine that runs a non-pruned full node
`scp [source] [target]`
# Install GO
`wget https://dl.google.com/go/go1.12.3.linux-amd64.tar.gz`
`sha256sum go1.12.3.linux-amd64.tar.gz | awk -F " " '{ print $1 }'`
# output should be `3924819eed16e55114f02d25d03e77c916ec40b7fd15c8acb5838b63135b03df`
`tar -C /usr/local -xzf go1.12.3.linux-amd64.tar.gz`
`export PATH=$PATH:/usr/local/go/bin`
# clone the btcwallet repo
`git clone https://github.com/btcsuite/btcwallet $GOPATH/src/github.com/btcsuite/btcwallet`
# run dropwtxmgr
`cd $GOPATH/src/github.com/btcsuite/btcwallet`
`GO111MODULE=on go install ./dropwtxmgr`
`cd $GOPATH/bin`
`dropwtxmgr --db=/path/to/data/chain/bitcoin/mainnet/wallet.db`
# Restart lnd, it should run a full rescan from genesis block, that might be a bit long though (24 hours on my machine)

Thanks for this, being an absolute newbie with Go and linux in general, this gave me a starting point.

In my case, I wanted to recover rescan an lnd instance using an existing mainnet btcpay deployment that I use for testing. Since the docker images used are alpine based, I ran into some trouble with the guide.

For running on alpine, I first ran before your guide:

apk update && apk add git 
apk --no-cache --allow-untrusted -X https://apkproxy.herokuapp.com/sgerrand/alpine-pkg-glibc add glibc glibc-bin

and instead of

`cd $GOPATH/src/github.com/btcsuite/btcwallet`
`GO111MODULE=on go install ./dropwtxmgr`
`cd $GOPATH/bin`
`dropwtxmgr --db=/path/to/data/chain/bitcoin/mainnet/wallet.db`

I did:

cd cmd/dropwtxmgr
go run main.go --db=/data/data/chain/bitcoin/mainnet/wallet.db

How long does the drop command take? Mine has been stuck there for a few mins now with no output:
Drop all btcwallet transaction history? [y/N] y

This is a horrible experience, no user should be needing to do this painful technical stuff to fix their lnd.

Haha, yes, it makes you realise that lightning is still hardcore now