Using dev-env Flake in Other Projects

This flake is designed to be used as a dependency in other flakes with full support for the follows mechanism, allowing you to control dependency versions from your parent flake.

Basic Usage

As a Direct Dependency

{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.05";
    dev-env.url = "github:devnw/dev-env";
  };

  outputs = { self, nixpkgs, dev-env }: {
    # Use dev-env packages directly
    devShells.default = dev-env.devShells.${system}.default;

    # Or use individual packages
    packages.fmt = dev-env.packages.${system}.fmt;
  };
}

Using `follows` for Dependency Management

The follows mechanism allows you to ensure all dependencies use the same version of nixpkgs and other inputs, avoiding duplicate downloads and potential version conflicts.

Recommended Pattern

{
  inputs = {
    # Your primary nixpkgs
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.05";
    nixpkgs-unstable.url = "github:NixOS/nixpkgs/nixos-unstable";

    # Shared utilities
    flake-utils.url = "github:numtide/flake-utils";

    # dev-env with follows for all its inputs
    dev-env = {
      url = "github:devnw/dev-env";
      inputs = {
        nixpkgs.follows = "nixpkgs";
        unstable.follows = "nixpkgs-unstable";
        flake-utils.follows = "flake-utils";
      };
    };
  };

  outputs = { self, nixpkgs, dev-env, flake-utils, ... }:
    flake-utils.lib.eachDefaultSystem (system: {
      devShells.default = dev-env.devShells.${system}.go;
    });
}

Available Inputs for `follows`

All dev-env inputs support follows:

nixpkgs - Main stable nixpkgs (currently 25.05)
unstable - Unstable nixpkgs for newer packages
flake-utils - Flake utilities for multi-system builds
gomod2nix - Go module tooling (auto-follows nixpkgs)
canary - Optional devnw canary tools (auto-follows nixpkgs)

Important: Don't Override `unstable` with Stable

WARNING: Do NOT make the unstable input follow your stable nixpkgs! This will prevent you from getting the latest versions of Go, Zig, and other tools.

❌ WRONG - Don't do this:

dev-env.inputs.unstable.follows = "nixpkgs";  # This makes unstable use stable packages!

✅ CORRECT - Do one of these:

# Option 1: Don't override unstable at all (recommended)
dev-env = {
  url = "github:devnw/dev-env";
  inputs.nixpkgs.follows = "nixpkgs";  # Only override stable nixpkgs
  # unstable will use dev-env's own unstable channel
};

# Option 2: Provide your own unstable channel
inputs = {
  nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.11";
  nixpkgs-unstable.url = "github:NixOS/nixpkgs/nixos-unstable";

  dev-env = {
    url = "github:devnw/dev-env";
    inputs = {
      nixpkgs.follows = "nixpkgs";
      unstable.follows = "nixpkgs-unstable";  # Use YOUR unstable
    };
  };
};

Using the Overlay

The dev-env flake provides an overlay that adds all development scripts to nixpkgs:

{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.05";
    dev-env.url = "github:devnw/dev-env";
  };

  outputs = { self, nixpkgs, dev-env }: {
    devShells.default = let
      pkgs = import nixpkgs {
        inherit system;
        overlays = [ dev-env.overlays.default ];
      };
    in pkgs.mkShell {
      buildInputs = [
        pkgs.dev-env-scripts.fmt
        pkgs.dev-env-scripts.lint
        # Other scripts available:
        # cex, upgrade, fuzz, fuzz-go, license, tag, godoc, pre-commit-global
      ];
    };
  };
}

Note: The overlay does not include the tidy script to avoid circular dependencies with gomod2nix. Use the package directly if you need tidy functionality.

Available Development Shells

dev-env.devShells.${system}.default  # Full development environment
dev-env.devShells.${system}.go       # Go development
dev-env.devShells.${system}.node     # Node.js development
dev-env.devShells.${system}.terraform # Infrastructure as code
dev-env.devShells.${system}.ansible  # Configuration management
dev-env.devShells.${system}.nix      # Nix development
dev-env.devShells.${system}.zig      # Zig development
dev-env.devShells.${system}.ui       # UI development (Node + testing)
dev-env.devShells.${system}.hugo     # Hugo static site development
dev-env.devShells.${system}.ci       # CI/CD tooling

Available Packages

Individual scripts and package collections:

# Individual scripts
dev-env.packages.${system}.fmt       # Multi-language formatter
dev-env.packages.${system}.lint      # Multi-language linter
dev-env.packages.${system}.cex       # Curl and execute utility
dev-env.packages.${system}.tidy      # Code cleanup (requires gomod2nix)
dev-env.packages.${system}.upgrade   # Dependency upgrader
dev-env.packages.${system}.fuzz      # Parallel fuzzing tool
dev-env.packages.${system}.fuzz-go   # Go fuzzing
dev-env.packages.${system}.license   # License header management
dev-env.packages.${system}.tag       # Version tagging utility

# Package collections
dev-env.packages.${system}.commonPackages    # Core development tools
dev-env.packages.${system}.goPackages        # Go toolchain
dev-env.packages.${system}.nodePackages      # Node.js tools
dev-env.packages.${system}.terraformPackages # Terraform tooling
dev-env.packages.${system}.ansiblePackages   # Ansible tooling
dev-env.packages.${system}.nixPackages       # Nix development tools
dev-env.packages.${system}.zigPackages       # Zig toolchain
dev-env.packages.${system}.uiPackages        # UI testing tools

Benefits of Using `follows`

Reduced Disk Usage: Only one copy of nixpkgs is downloaded
Faster Evaluation: Nix doesn't need to evaluate multiple nixpkgs versions
Version Consistency: All dependencies use the same package versions
Easier Updates: Update nixpkgs once, all dependencies follow
Predictable Builds: Avoid conflicts from different nixpkgs versions

Troubleshooting

Canary Input Not Available

The canary input is optional and gracefully degrades if not available. If the canary flake doesn't export the expected packages, the flake will use an empty list and continue working normally.

If you want to completely override it:

dev-env = {
  url = "github:devnw/dev-env";
  inputs = {
    nixpkgs.follows = "nixpkgs";
    # You can override canary to point to your own flake
    canary.url = "github:yourorg/your-canary-fork";
  };
};

Darwin SDK Deprecation Warning

On macOS systems, you may see a warning:

evaluation warning: darwin.apple_sdk_11_0.callPackage: deprecated and will be removed in Nixpkgs 25.11

This is a known nixpkgs internal warning from transitive dependencies (like docker-credential-helpers). It's not an error and doesn't affect functionality. The warning will be resolved when upgrading to nixpkgs 25.11 or later. You can safely ignore it for now.

Zig Version Compatibility

The flake automatically selects the best available Zig version from your nixpkgs-unstable:

Prefers zig_0_15 if available
Falls back to zig_0_14, zig_0_13, or the latest zig package
ZLS (Zig Language Server) and zig-zlint are optional and gracefully excluded if not available

This ensures the flake works across different versions of nixpkgs-unstable without errors. If you need a specific Zig version, you can override the unstable input in your parent flake to point to a nixpkgs version that includes your desired Zig version.

gomod2nix Conflicts

If you have your own gomod2nix setup:

dev-env = {
  url = "github:devnw/dev-env";
  inputs = {
    gomod2nix.follows = "gomod2nix";  # Use your gomod2nix
  };
};

Example: Full Integration

{
  description = "My project using dev-env";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.05";
    nixpkgs-unstable.url = "github:NixOS/nixpkgs/nixos-unstable";
    flake-utils.url = "github:numtide/flake-utils";

    dev-env = {
      url = "github:devnw/dev-env";
      inputs = {
        nixpkgs.follows = "nixpkgs";
        unstable.follows = "nixpkgs-unstable";
        flake-utils.follows = "flake-utils";
      };
    };
  };

  outputs = { self, nixpkgs, dev-env, flake-utils, ... }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = import nixpkgs {
          inherit system;
          config.allowUnfree = true;
        };
      in
      {
        devShells = {
          # Use dev-env's Go shell
          default = dev-env.devShells.${system}.go;

          # Or create a custom shell with dev-env packages
          custom = pkgs.mkShell {
            buildInputs = with dev-env.packages.${system}; [
              fmt
              lint
              commonPackages
              goPackages
            ];
          };
        };

        # Use dev-env scripts in your CI
        packages.ci-check = pkgs.writeShellScriptBin "ci-check" ''
          ${dev-env.packages.${system}.fmt}/bin/fmt --check
          ${dev-env.packages.${system}.lint}/bin/lint
        '';
      }
    );
}

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Using dev-env Flake in Other Projects

Basic Usage

As a Direct Dependency

Using `follows` for Dependency Management

Recommended Pattern

Available Inputs for `follows`

Important: Don't Override `unstable` with Stable

Using the Overlay

Available Development Shells

Available Packages

Benefits of Using `follows`

Troubleshooting

Canary Input Not Available

Darwin SDK Deprecation Warning

Zig Version Compatibility

gomod2nix Conflicts

Example: Full Integration

See Also

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File metadata and controls

Using dev-env Flake in Other Projects

Basic Usage

As a Direct Dependency

Using follows for Dependency Management

Recommended Pattern

Available Inputs for follows

Important: Don't Override unstable with Stable

Using the Overlay

Available Development Shells

Available Packages

Benefits of Using follows

Troubleshooting

Canary Input Not Available

Darwin SDK Deprecation Warning

Zig Version Compatibility

gomod2nix Conflicts

Example: Full Integration

See Also

Using `follows` for Dependency Management

Available Inputs for `follows`

Important: Don't Override `unstable` with Stable

Benefits of Using `follows`