Usage

system :: { system = system, ... }

system={x86_64-linux="x86_64-linux";x86_64-darwin="x86_64-darwin";  ...}

allSystems :: [<system>]

defaultSystems :: [<system>]

{# 1. Defined a "systems" inputs that maps to only ["x86_64-linux"]inputs.systems.url="github:nix-systems/x86_64-linux";inputs.flake-utils.src="github:numtide/flake-utils";# 2. Override the flake-utils default to your versioninputs.flake-utils.inputs.systems.follows="systems";outputs={self,flake-utils, ...}:# Now eachDefaultSystem is only using ["x86_64-linux"], but this list can also# further be changed by users of your flake.flake-utils.lib.eachDefaultSystem(system:{# ...});}

eachSystem :: [<system>] -> (<system> -> attrs)

eachSystem[system.x86_64-linux](system:{hello=42;})# => { hello = { x86_64-linux = 42; }; }eachSystemallSystems(system:{hello=42;})# => {hello.aarch64-darwin=42,hello.aarch64-genode=42,hello.aarch64-linux=42,   ...hello.x86_64-redox=42,hello.x86_64-solaris=42,hello.x86_64-windows=42}

eachDefaultSystem :: (<system> -> attrs)

Example

{description="Flake utils demo";inputs.flake-utils.url="github:numtide/flake-utils";outputs={self,nixpkgs,flake-utils}:flake-utils.lib.eachDefaultSystem(system:letpkgs=nixpkgs.legacyPackages.${system};in{packages=rec{hello=pkgs.hello;default=hello;};apps=rec{hello=flake-utils.lib.mkApp{drv=self.packages.${system}.hello;};default=hello;};});}

mkApp { drv, name ? drv.pname or drv.name, exePath ? drv.passthru.exePath or "/bin/${name}"

flattenTree :: attrs -> attrs

flattenTree{hello=pkgs.hello;gitAndTools=pkgs.gitAndTools}

{hello= «derivation»;"gitAndTools/git"= «derivation»;"gitAndTools/hub"= «derivation»;# ...}

simpleFlake :: attrs -> attrs

{# pass an instance of selfself,# pass an instance of the nixpkgs flakenixpkgs,# we assume that the name maps to the project name, and also that the# overlay has an attribute with the `name` prefix that contains all of the# project's packages.name,# nixpkgs configconfig ?{},# pass either a function or a fileoverlay ?null,# use this to load other flakes overlays to supplement nixpkgspreOverlays ?[],# maps to the devShell output. Pass in a shell.nix file or function.shell ?null,# pass the list of supported systemssystems ?["x86_64-linux""aarch64-linux""x86_64-darwin""aarch64-darwin"]}:null

Example

{description="Flake utils demo";inputs.flake-utils.url="github:numtide/flake-utils";outputs={self,nixpkgs,flake-utils}:flake-utils.lib.simpleFlake{inheritselfnixpkgs;name="simple-flake";overlay=./overlay.nix;shell=./shell.nix;};}