Lunatic#

Lunatic is detected if both

a Cargo.toml file is found and
.cargo/config.toml has the runner = "lunatic"

For example .cargo/config.toml:

[build]
target = "wasm32-wasi"

[target.wasm32-wasi]
runner = "lunatic"

Setup#

By default the latest stable version of Rust available in this rust-overlay is used. The version can be overridden with either

a .rust-version file
The rust-version property of Cargo.toml
setting the NIXPACKS_RUST_VERSION environment variable
A rust-toolchain.toml file

Build#

cargo build --release

Start#

The binaries get .wasm suffix and will be ran with the lunatic runtime.

If your project has multiple binaries, you can specify which one to run with the NIXPACKS_RUST_BIN environment variable. Optionally, it can be overriden with the default_run property in Cargo.toml under the [package] section.

./target/wasm32-wasi/release/{name}.wasm

Caching#

These directories are cached between builds

Build: ~/.cargo/git
Build: ~/.cargo/registry
Build: target

Workspaces#

Nixpacks will auto-detect if you are using Cargo Workspaces. This checks workspace.default_members first and then workspace.members. It also respects the workspace.exclude field.

To set which workspace Nixpacks will build, just set the NIXPACKS_CARGO_WORKSPACE environment variable and Nixpacks will use it as the --package argument.