With this release, eclair requires using Bitcoin Core 27.1.
Newer versions of Bitcoin Core may be used, but have not been extensively tested.
This version introduces a new coin selection algorithm called [CoinGrinder](https://github.com/bitcoin/bitcoin/blob/master/doc/release-notes/release-notes-27.0.md#wallet) that will reduce on-chain transaction costs when feerates are high.
To enable CoinGrinder at all fee rates and prevent the automatic consolidation of UTXOs, add the following line to your `bitcoin.conf` file:
You will need `gpg` and our release signing key 7A73FE77DE2C4027. Note that you can get it:
- from our website: https://acinq.co/pgp/drouinf.asc
- from github user @sstone, a committer on eclair: https://api.github.com/users/sstone/gpg_keys
To import our signing key:
```sh
$ gpg --import drouinf.asc
```
To verify the release file checksums and signatures:
```sh
$ gpg -d SHA256SUMS.asc > SHA256SUMS.stripped
$ sha256sum -c SHA256SUMS.stripped
```
## Building
Eclair builds are deterministic. To reproduce our builds, please use the following environment (*):
- Ubuntu 22.04
- AdoptOpenJDK 11.0.22
- Maven 3.9.2
Use the following command to generate the eclair-node package:
```sh
mvn clean install -DskipTests
```
That should generate `eclair-node/target/eclair-node-<version>-XXXXXXX-bin.zip` with sha256 checksums that match the one we provide and sign in `SHA256SUMS.asc`
(*) You may be able to build the exact same artefacts with other operating systems or versions of JDK 11, we have not tried everything.
## Upgrading
This release is fully compatible with previous eclair versions. You don't need to close your channels, just stop eclair, upgrade and restart.
