nixos-build

name	nixos-build
description	Validate NixOS configuration changes by running nh os build and interpreting errors
compatibility	opencode

What I do

After making changes to any .nix files in this repository, run nh os build to validate the configuration evaluates and builds without errors.

How to run

git add -AN
nh os build

Run from the repo root (/home/vidhanio/Projects/vidhanix). The build typically takes 10–60 seconds.

Important: Always stage relevant files with git add before running nh os build. The build uses staged files, so unstaged changes won't be included. Usually git add -AN is appropriate, but you can stage specific files/directories with intent-to-add if needed (e.g., git add -N modules/programs/neovim/).

Interpreting output

• Success: output ends with ✔ nixos-system-... and a SIZE / DIFF summary. No action needed.
• Evaluation error (error: ...): a Nix expression is invalid. Read the error trace to find the offending file and line, fix it, and re-run.
• Missing path (path '...' does not exist): a relative path to a secret or file is wrong. Count the directory depth of the referencing .nix file relative to the repo root and correct the ../ prefix count so it resolves to secrets/<name>.age at the repo root.
• Type/option error (The option ... does not exist / is not of type): a Home Manager or NixOS option is misused. Check the module definition and fix the value or type.

When to use

Use this skill any time .nix files are created or modified — especially when touching:

• age.secrets.*.file paths
• New module options or config blocks
• Package definitions or perSystem expressions
• Any file under modules/

Always run before declaring a task complete.