Tutorial: Develop a Rust package using pixi

In this tutorial, we will show you how to develop a Rust package using pixi. The tutorial is written to be executed from top to bottom, missing steps might result in errors.

The audience for this tutorial is developers who are familiar with Rust and cargo and how are interested to try pixi for their development workflow. The benefit would be within a rust workflow that you lock both rust and the C/System dependencies your project might be using. E.g tokio users will almost most definitely use openssl.

If you're new to pixi, you can check out the basic usage guide. This will teach you the basics of pixi project within 3 minutes.

Prerequisites

• You need to have pixi installed. If you haven't installed it yet, you can follow the instructions in the installation guide. The crux of this tutorial is to show you only need pixi!

Create a pixi project.

pixi init my_rust_project
cd my_rust_project

It should have created a directory structure like this:

my_rust_project
├── .gitattributes
├── .gitignore
└── pixi.toml

The pixi.toml file is the manifest file for your project. It should look like this:

pixi.toml

[project]
name = "my_rust_project"
version = "0.1.0"
description = "Add a short description here"
authors = ["User Name <user.name@email.url>"]
channels = ["conda-forge"]
platforms = ["linux-64"] # (1)!

[tasks]

[dependencies]

1. The platforms is set to your system's platform by default. You can change it to any platform you want to support. e.g. ["linux-64", "osx-64", "osx-arm64", "win-64"].

Add Rust dependencies

To use a pixi project you don't need any dependencies on your system, all the dependencies you need should be added through pixi, so other users can use your project without any issues.

pixi add rust

This will add the rust package to your pixi.toml file under [dependencies]. Which includes the rust toolchain, and cargo.

Add a cargo project

Now that you have rust installed, you can create a cargo project in your pixi project.

pixi run cargo init

pixi run is pixi's way to run commands in the pixi environment, it will make sure that the environment is set up correctly for the command to run. It runs its own cross-platform shell, if you want more information checkout the tasks documentation. You can also activate the environment in your own shell by running pixi shell, after that you don't need pixi run ... anymore.

Now we can build a cargo project using pixi.

pixi run cargo build

To simplify the build process, you can add a build task to your pixi.toml file using the following command:

pixi task add build "cargo build"

Which creates this field in the pixi.toml file:

pixi.toml

[tasks]
build = "cargo build"

And now you can build your project using:

pixi run build

You can also run your project using:

pixi run cargo run

Which you can simplify with a task again.

pixi task add start "cargo run"

So you should get the following output:

pixi run start
Hello, world!

Congratulations, you have a Rust project running on your machine with pixi!

Next steps, why is this useful when there is rustup?

Cargo is not a binary package manager, but a source-based package manager. This means that you need to have the Rust compiler installed on your system to use it. And possibly other dependencies that are not included in the cargo package manager. For example, you might need to install openssl or libssl-dev on your system to build a package. This is the case for pixi as well, but pixi will install these dependencies in your project folder, so you don't have to worry about them.

Add the following dependencies to your cargo project:

pixi run cargo add git2

If your system is not preconfigured to build C and have the libssl-dev package installed you will not be able to build the project:

pixi run build
...
Could not find directory of OpenSSL installation, and this `-sys` crate cannot
proceed without this knowledge. If OpenSSL is installed and this crate had
trouble finding it,  you can set the `OPENSSL_DIR` environment variable for the
compilation process.

Make sure you also have the development packages of openssl installed.
For example, `libssl-dev` on Ubuntu or `openssl-devel` on Fedora.

If you're in a situation where you think the directory *should* be found
automatically, please open a bug at https://github.com/sfackler/rust-openssl
and include information about your system as well as this message.

$HOST = x86_64-unknown-linux-gnu
$TARGET = x86_64-unknown-linux-gnu
openssl-sys = 0.9.102


It looks like you're compiling on Linux and also targeting Linux. Currently this
requires the `pkg-config` utility to find OpenSSL but unfortunately `pkg-config`
could not be found. If you have OpenSSL installed you can likely fix this by
installing `pkg-config`.
...

You can fix this, by adding the necessary dependencies for building git2, with pixi:

pixi add openssl pkg-config compilers

Now you should be able to build your project again:

pixi run build
...
   Compiling git2 v0.18.3
   Compiling my_rust_project v0.1.0 (/my_rust_project)
    Finished dev [unoptimized + debuginfo] target(s) in 7.44s
     Running `target/debug/my_rust_project`

Extra: Add more tasks

You can add more tasks to your pixi.toml file to simplify your workflow.

For example, you can add a test task to run your tests:

pixi task add test "cargo test"

And you can add a clean task to clean your project:

pixi task add clean "cargo clean"

You can add a formatting task to your project:

pixi task add fmt "cargo fmt"

You can extend these tasks to run multiple commands with the use of the depends-on field.

pixi task add lint "cargo clippy" --depends-on fmt

Conclusion

In this tutorial, we showed you how to create a Rust project using pixi. We also showed you how to add dependencies to your project using pixi. This way you can make sure that your project is reproducible on any system that has pixi installed.

Show Off Your Work!

Finished with your project? We'd love to see what you've created! Share your work on social media using the hashtag #pixi and tag us @prefix_dev. Let's inspire the community together!