How does this skill handle config-dependent checks?

The skill teaches you to nest mkIf inside optionalAttrs, allowing the platform check to happen at parse time while keeping the configuration check lazy.

Why shouldn't I use mkIf for platform checks in Nix?

mkIf is evaluated lazily, but the option path remains visible during evaluation. If an option doesn't exist on a specific platform, Nix will throw an error even if the mkIf condition is false.

Can this skill help debug existing Nix evaluation errors?

Yes, it includes specific grep commands and patterns to identify problematic config references and platform guards in your existing codebase.

What is the primary benefit of the Nix Platform-Specific Options skill?

It provides a standardized pattern to write Nix modules that work across NixOS and Darwin without causing infinite recursion or 'option not found' errors.

Nix Platform Module Manager

Name: Nix Platform Module Manager
Author: edmundmiller

byedmundmiller

•

Deployment & DevOps

Writes robust Nix modules for NixOS and Darwin by implementing patterns that prevent infinite recursion and evaluation errors.

This skill provides specialized guidance for creating cross-platform Nix modules, specifically addressing the challenges of sharing configurations between NixOS and macOS (nix-darwin). It solves the common 'infinite recursion' problem by establishing clear boundaries between parse-time platform checks using optionalAttrs and lazy-evaluated configuration checks using mkIf. By following these established patterns, developers can create maintainable dotfiles and system configurations that gracefully handle platform-specific options without triggering evaluation failures.

Key Features

01Debugging strategies for common Nix module evaluation errors

02Nested configuration patterns for platform-specific services

03Cross-platform logic for NixOS and Darwin systems

0442 GitHub stars

05Clear differentiation between optionalAttrs and mkIf usage

06Infinite recursion prevention using optimized evaluation patterns

Use Cases

01Creating a single Nix module that manages shell aliases on both Linux and macOS

02Refactoring dotfiles to resolve 'option does not exist' errors in multi-platform setups

03Implementing conditional system services that depend on both the OS type and user configuration

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add edmundmiller/dotfiles nix-platform-specific-options

For use in Claude.ai and ChatGPT

Download Skill