# Building Liana

We use [Cargo](https://doc.rust-lang.org/stable/cargo/), the ubiquitous Rust package manager.
Cargo takes care of downloading and compiling the project's dependencies, as well as compiling the
project itself. Dependencies are specified in a [`Cargo.toml`](../Cargo.toml) file at the root of
this repository. They are pinned in a [`Cargo.lock`](../Cargo.lock) file at the same place.

We take security very seriously, and toolchain is a big part of that. We are moderately conservative
with dependencies and aim to target reasonable compiler versions that have had time to mature (ie
that had the chance to be reviewed and distributed by third parties, as well as tested by the
community).  See [`CONTRIBUTING.md`](../CONTRIBUTING.md) for the currently minimum Rust version
supported by `lianad`.

To build the GUI too, you'll unfortunately need a more recent Rust version. The minimum version
supported by the GUI at the moment is `1.65`. You will most likely have to [manually download
it](#by-manually-downloading-the-latest-stable-version) or [use `rustup`](#through-rustup) to
install more recent compilers.


## Getting `Cargo`

### Through your system package manager

Most package managers distribute a version of `Cargo` able to build this project. For instance on
Debian-based systems (as root):
```
apt update && apt install cargo
```

### By manually downloading the latest stable version

The ["other installation
methods"](https://forge.rust-lang.org/infra/other-installation-methods.html#standalone-installers)
page of the Rust website contains a list of archives for different architectures, along with
signatures made with the ["Rust signing key"](https://static.rust-lang.org/rust-key.gpg.ascii):
```
pub   rsa4096/0x85AB96E6FA1BE5FE 2013-09-26 [SC]
      Key fingerprint = 108F 6620 5EAE B0AA A8DD  5E1C 85AB 96E6 FA1B E5FE
uid                   [ unknown] Rust Language (Tag and Release Signing Key) <rust-key@rust-lang.org>
sub   rsa4096/0x8E9AA3F7AB3F5826 2013-09-26 [E]
sub   rsa4096/0x5CB4A9347B3B09DC 2014-12-15 [S]
```

You can therefore pull the key from either the above or from a keyserver:
```
$ gpg --keyserver hkps://keys.openpgp.org --receive 108F66205EAEB0AAA8DD5E1C85AB96E6FA1BE5FE
```

And then you can download the archive corresponding to your system and CPU architecture, verify the
signature and use the `cargo` binary from this archive to build Liana. Here is an example for
`amd64`:
```
$ curl -O https://static.rust-lang.org/dist/rust-1.65.0-x86_64-unknown-linux-gnu.tar.gz
$ curl -O https://static.rust-lang.org/dist/rust-1.65.0-x86_64-unknown-linux-gnu.tar.gz.asc
$ gpg --verify rust-1.65.0-x86_64-unknown-linux-gnu.tar.gz.asc
$ tar -xzf rust-1.65.0-x86_64-unknown-linux-gnu.tar.gz
$ ./rust-1.65.0-x86_64-unknown-linux-gnu/cargo/bin/cargo build --release
```

### Through `rustup`

[`rustup`](https://rust-lang.github.io/rustup/) is a software for installing the Rust toolchain.

Some package managers distribute a version of `rustup`. Failing that, you can always follow the
"official" [installation method of `rustup`](https://www.rust-lang.org/tools/install) (that is, a
`curl`-`sh` pipe).


## Building the project

Once you've got Cargo, building the project is a simple `cargo` invocation away.

To only build the daemon, run it from the root of the repository:
```
$ cargo build --release
```
The `lianad` and `liana-cli` binaries will be in the `target/` directory at the root of the
repository:
```
$ ls target/release/
build  deps  examples  incremental  liana-cli  liana-cli.d  lianad  lianad.d  libliana.d  libliana.rlib
```

To build the whole wallet including the GUI, you'll need to install its [build and runtime
dependencies](https://github.com/wizardsardine/liana/tree/master/gui#dependencies) first. Then run
the same command as above within the [`gui/`](../gui/) folder present at the root of the repository:
```
$ cd gui/
$ cargo build --release
```
The `liana-gui` binary will be in the `target/` folder:
```
$ ls target/release/
build  deps  examples  incremental  liana-gui  liana-gui.d  libliana_gui.d  libliana_gui.rlib
```

Whether your are building the whole wallet or only the daemon, make sure not to forget the
`--release` command line option. You would otherwise build without optimizations.