nix-module-system SKILL.md skillC
nix-module-system from ypares/rigup.nix is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add ypares/rigup.nix/nix-module-system@git:20251216.c94188fPins git:20251216.c94188f in mdr.lock. Pin the fingerprint instead.
- Audit grade
- C, 14 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- ypares/rigup.nix
- Path
riglets/nix-module-system/SKILL.md- Versions recorded
- 1
- Latest version
- git:20251216.c94188f, committed Dec 16, 2025
- Size
- 4,537 bytes
- Repository stars
- 95
- License
- MIT
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Nix Module System: Dark Corners
Practical knowledge about `lib.evalModules` that's hard to find in official docs.
**Sources:**
- [nixpkgs/lib/modules.nix](https://github.com/NixOS/nixpkgs/blob/master/lib/modules.nix) — implementation
- [Module system docs](https://github.com/NixOS/nixpkgs/blob/master/doc/module-system/module-system.chapter.md) — official chapter
- [nix.dev deep dive](https://nix.dev/tutorials/module-system/deep-dive.html) — tutorial
- [noogle.dev evalModules](https://noogle.dev/f/lib/modules/evalModules) — function reference
## Module Identity & Deduplication
When the same module is included multiple times (e.g., via imports from different places), `evalModules` deduplicates by identity:
**Path-based modules**: Deduplicated by path string
```nix
modules = [ ./foo.nix ./foo.nix ]; # Same path → evaluated once
```
**Function/attrset modules**: Deduplicated by `key` attribute
```nix
# Without key: each inclusion is separate (can cause "defined multiple times" errors)
modules = [ myModule myModule ]; # Evaluated twice!
# With key: deduplicated
myModule = {
key = "my-unique-module-id";
imports = [ actualModule ];
};
…Read the whole file at its exact version.
How to install
mdr add ypares/rigup.nix/nix-module-system@sha256:00d83070c05f4c00The line at the top of this page pins the label git:20251216.c94188f, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_chy4svnyg5lkw34l)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on Dec 16, 2025.
Audit of the latest version
- fail: Frontmatter block present
- fail: Frontmatter declares a name
- fail: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (4537 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Starting a new one? Use a template for SKILL.md on mdpantry, which passes every one of these checks and says what to change in it.
Source
ypares/rigup.nix · 95 stars · license MIT · pushed 2026-10-21 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_chy4svnyg5lkw34l GET https://markdownregistry.com/api/v1/resolve?ref=ypares/rigup.nix/nix-module-system GET https://markdownregistry.com/api/v1/blob/00d83070c05f4c007c404039e71596166063522de09906ffc40832b7df04b4d5
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.