V3 Contributing Guide

Getting Started

Start a development container (which includes NDC agents for testing):

docker compose run --build --rm dev_setup bash

You will need to install some packages:

For development, you may need to install some additional tools such as nextest. See the Dockerfile.

If the dependencies are correctly installed as above, you should now be able to run

cargo build

From here, you can follow the instructions in <README.md> to set up a working server.

We maintain a Nix Flake that will install all of the project dependencies required to work on v3-engine.

To use it:

Install Nix
Run nix develop in the project root. This starts a new shell which exposes the Nix project dependencies on your $PATH, and can be exited with exit.
Type echo $IN_NIX_SHELL to confirm you're in a Nix shell. It should print "impure".
Run which rustc to verify that the Rust compiler is being provided by Nix. You should see a path starting with /nix/store/ and ending in /bin/rustc.

We also supply configuration for direnv to allow autoloading the Nix dependencies upon entering the project folder.

To use this:

Install direnv:
Install the direnv program
Add the direnv hook to your shell
Open a new terminal
cp .envrc.local.example .envrc.local
Run direnv allow
Nix should now install project dependencies and put them in your $PATH whenever you enter the project folder.
Type echo $IN_NIX_SHELL to confirm you're in a Nix shell. It should print "impure".
Run which rustc to verify that the Rust compiler is being provided by Nix. You should see a path starting with /nix/store/ and ending in /bin/rustc.

When starting the engine, you can use the UNSTABLE_FEATURES env var to enable work in progress features. Currently available:

enable-boolean-expression-types - allow the new BooleanExpressionType metadata kind