lnd v0.10.2-beta

This marks the second minor release in the `v0.10.0` series! This release allows `lnd` to be compatible with `bitcoind 0.20`, resolves some peer connection instability issues, fixes an issue that can cause payments to hang ina state until a connection is cycled, and **fixes an important bug** related to an on disk Static Channel Backups (SCB). # Verifying the Release In order to verify the release, you'll need to have `gpg` or `gpg2` installed on your system. Once you've obtained a copy (and hopefully verified that as well), you'll first need to import the keys that have signed this release if you haven't done so already: ``` curl https://keybase.io/roasbeef/pgp_keys.asc | gpg --import ``` Once you have the required PGP keys, you can verify the release (assuming `manifest-v0.10.2-beta.txt` and `manifest-v0.10.2-beta.txt.sig` are in the current directory) with: ``` gpg --verify manifest-v0.10.2-beta.txt.sig ``` You should see the following if the verification was successful: ``` gpg: assuming signed data in 'manifest-v0.10.2-beta.txt' gpg: Signature made Mon Jul 6 12:33:41 2020 PDT gpg: using RSA key 4AB7F8DA6FAEBB3B70B1F903BC13F65E2DC84465 gpg: Good signature from "Olaoluwa Osuntokun " [ultimate] ``` That will verify the signature of the manifest file, which ensures integrity and authenticity of the archive you've downloaded locally containing the binaries. Next, depending on your operating system, you should then re-compute the `sha256` hash of the archive with `shasum -a 256 `, compare it with the corresponding one in the manifest file, and ensure they match *exactly*. ## Verifying the Release Binaries Our release binaries are fully reproducible. Third parties are able to verify that the release binaries were produced properly without having to trust the release manager(s). See our [reproducible builds guide](https://github.com/lightningnetwork/lnd/tree/master/build/release) for how this can be achieved. The release binaries are compiled with `go1.14.4`, which is required by verifiers to arrive at the same ones. They include the following build tags: `autopilotrpc`, `signrpc`, `walletrpc`, `chainrpc`, `invoicesrpc`, `routerrpc`, and `watchtowerrpc`. Note that these are already included in the release script, so they do not need to be provided. The `make release` command can be used to ensure one rebuilds with all the same flags used for the release. If one wishes to build for only a single platform, then `make release sys= tag=` can be used. Finally, you can also verify the _tag_ itself with the following command: ``` git verify-tag v0.10.2-beta ``` # Building the Contained Release Users are able to rebuild the target release themselves without having to fetch any of the dependencies. In order to do so, assuming that `vendor.tar.gz` and `lnd-source-v0.10.2-beta.tar.gz` are in the current directory, follow these steps: ``` tar -xvzf vendor.tar.gz tar -xvzf lnd-source-v0.10.2-beta.tar.gz GO111MODULE=on go install -v -mod=vendor -ldflags "-X github.com/lightningnetwork/lnd/build.Commit=v0.10.2-beta" ./cmd/lnd GO111MODULE=on go install -v -mod=vendor -ldflags "-X github.com/lightningnetwork/lnd/build.Commit=v0.10.2-beta" ./cmd/lncli ``` The `-mod=vendor` flag tells the `go build` command that it doesn't need to fetch the dependencies, and instead, they're all enclosed in the local vendor directory. Additionally, it's now possible to use the [enclosed `release.sh` script to bundle a release for a _specific_ system like so](https://github.com/lightningnetwork/lnd/pull/2191): ``` make release sys="linux-arm64 darwin-amd64" ``` ⚡️⚡️⚡️ OK, now to the rest of the release notes! ⚡️⚡️⚡️ # Release Notes ## Network Gossip Channel Announcement Feature Bit Encoding This release fixes an existing bug that would cause us to not carry over the `ChannelUpdate` level feature bits when sending a channel announcement suit to a connected node. Some nodes have started to use this space to communicate that they support "wumbo" channels. Before this change, if `lnd` was instructed to send the channel announcement for a wumbo channel, it would omit this feature bit information, causing the requesting node to reject the announcement as the signature would fail. This may have cause some peer connection instability since these wumbo channels have started to be more widely propagated across the network. ## Synchronous Switch <-> Link HTLC Handoff This release modifies the way a new payment is sent to the first outgoing channel it needs to traverse before being sent off to the network. Before this commit, the router would hand the payment off to the switch in an asynchronous manner. Recently, it was brought to our attention that this behavior could at times cause a payment to unnecessarily fail later if the target link wasn't online, or not fully available. [In this new release, this process is now synchronous](https://github.com/lightningnetwork/lnd/pull/4183). End users should observe that they see less internal payment failures due to out of date bandwidth hints, as is now able to full see through the addition of a new HTLC. ## bitcoind Compatibility With this new release, `lnd` can now be used with `bitcoind 0.20` as it's full-node chain backend. ## SCB Bug Fix [This release includes an **important bug fix for static channel backups**](https://github.com/lightningnetwork/lnd/pull/4379). Before this release, if a _new_ `lnd` node was started with a data directory that contained an _existing_ SCB file, then that existing file would be completely overridden by whatever channel state the new `lnd` node started with. With this new release, of `lnd`, we'll fail to start if we're unable to read an existing SCB file on disk. Additionally, we'll always _combine_ the contents of the SCB file with our in-memory channel state. The full list of changes since `v0.10.1-beta` can be found here: * https://github.com/lightningnetwork/lnd/compare/v0.10.1-beta...v0.10.2-beta-branch # Contributors (Alphabetical Order) Andras Banki-Horvath Olaoluwa Osuntokun Oliver Gugger Joost Jager Wilmer Paulino