Build Helpers

These builders come from the shared ScottyLabs devenv flake as mkLib, a function applied to a pkgs set (the same shape as crane.mkLib). Add the flake as an input, then call a helper per system:

# flake.nix inputs
scottylabs = {
  url = "git+https://codeberg.org/ScottyLabs/devenv";
  inputs.nixpkgs.follows = "nixpkgs";
};

# in outputs
pkgs = nixpkgs.legacyPackages.${system};
kennel = (scottylabs.mkLib pkgs).buildRustService { ... };

Each helper takes the consumer’s pkgs, so packages build against your nixpkgs pin rather than the shared flake’s.

buildRustService

Builds a Rust crate with crane, caching dependencies separately from the build.

src

Crate or workspace root. Passed through craneLib.cleanCargoSource, so only Cargo-relevant files enter the build.

Type: path, required

pname

Package name. When unset, it is read from the pname field of Cargo.toml. A workspace has a virtual manifest with no package name, so a workspace must set this explicitly.

Type: nullOr str, default: null

version

Package version. When unset, it is read from the version field of Cargo.toml.

Type: nullOr str, default: null

nativeBuildInputs

Build-time tools, applied to both the dependency build and the final build. For example pkg-config or makeWrapper.

Type: listOf package, default: [ ]

buildInputs

Libraries to link against, applied to both the dependency build and the final build. For example openssl.

Type: listOf package, default: [ ]

buildArgs

Build-only options forwarded to crane’s buildPackage, kept separate from the arguments above so changing them never rebuilds the cached dependencies. doCheck defaults to false. Common keys are cargoExtraArgs to select a workspace member such as "-p kennel", and postInstall to wrap the binary.

Type: attrs, default: { }

(scottylabs.mkLib pkgs).buildRustService {
  src = ./.;
  pname = "kennel";
  version = "0.1.0";
  buildArgs.cargoExtraArgs = "-p kennel";
}

buildDenoTask

Builds a Deno project that has npm dependencies, running a deno task and copying its output directory. On Linux it patches the prebuilt native addons and drops the musl variants, which cannot be patched against a glibc host.

src

Directory holding deno.lock and deno.json.

Type: path, required

pname

Package name.

Type: str, required

version

Package version.

Type: str, default: "0.1.0"

task

The deno task to run.

Type: str, default: "build"

output

Directory the task emits, copied verbatim to the result.

Type: str, default: "dist"

entrypoint

Passed to deno install --entrypoint so dependency resolution ignores dependencies not reachable from it, such as test-only dependencies.

Type: nullOr str, default: null

compile

Provision denort so deno compile runs inside the offline build sandbox. Enable when the task compiles a binary instead of emitting a dist directory.

Type: bool, default: false

(scottylabs.mkLib pkgs).buildDenoTask {
  src = ./sites/web;
  pname = "link-shortener-web";
  version = "0.1.0";
}

buildPythonService

Builds a uv project into a virtual environment with uv2nix, resolving every dependency from uv.lock as a Nix derivation. The result is a relocatable venv exposing each [project.scripts] entry under bin/, consumed as ${pkg}/bin/<script>.

src

Project root holding pyproject.toml and uv.lock. The package name is read from pyproject.toml.

Type: path, required

python

The Python interpreter the environment is built against.

Type: package, default: pkgs.python3

sourcePreference

Whether dependencies come from prebuilt wheels ("wheel") or are built from source ("sdist"). The build-system overlay is matched to this choice automatically.

Type: str, default: "wheel"

selectDeps

Selects the locked dependency closure to install from the loaded workspace. Override to install an optional group, for example ws: ws.deps.optionals.prod.

Type: function, default: ws: ws.deps.default

overrides

An overlay applied last over the Python package set, to supply system libraries or build tools uv2nix cannot infer for a package built from source (for example adding pkgs.openssl to buildInputs).

Type: function, default: _final: _prev: { }

(scottylabs.mkLib pkgs).buildPythonService {
  src = ./.;
}

buildMdbook

Builds an mdBook site to the result.

src

Directory holding book.toml.

Type: path, required

name

Derivation name.

Type: str, default: "docs"

(scottylabs.mkLib pkgs).buildMdbook {
  src = ./sites/docs;
  name = "kennel-docs";
}