Shikaku — Native NixOS Puzzle Game

A fully offline, ad-free Shikaku rectangle puzzle game. Built with Python + GTK4. Packaged to nixpkgs standards.

What is Shikaku?

Divide the grid into rectangles. Each rectangle must:

• Contain exactly one number clue
• Have an area (in cells) equal to that number

All puzzles are procedurally generated and guaranteed solvable — the generator works backwards, partitioning the grid into valid rectangles first and then placing clue numbers, so every puzzle has a solution by construction.

Controls

Action	Input
Draw a rectangle	Click and drag across cells
Erase a rectangle	Right-click any cell inside it
Check your solution	Click Check
New puzzle	Click New Puzzle
Clear all	Click Clear

Puzzle sizes

Size	Status
5×5	✅
7×7	✅
10×10	🔜
15×15	🔜
20×20	🔜
25×25	🔜

---

TODO

• Fix window size to auto resize when changing game mode
• Show number of cells selected during a mouse drag, before placing
• Remove ability to select just 1 cell
• Add some kind of zoom feature
  • Scroll wheel
  • and/or a ui button for zoom in/out
• Remove red color from rectangle option

Possible Features

• Keep local "high score" for each puzzle type

---

Using the package locally (before it lands in nixpkgs)

Quick test with nix-build

Copy the pkgs/by-name/sh/shikaku/ directory into your local nixpkgs checkout, then from the nixpkgs root:

nix-build -A shikaku
./result/bin/shikaku

Install into your profile

nix-env -f '<nixpkgs>' -iA shikaku

In your NixOS configuration.nix (via an overlay)

nixpkgs.overlays = [
  (final: prev: {
    shikaku = final.callPackage /path/to/pkgs/by-name/sh/shikaku/package.nix { };
  })
];

environment.systemPackages = [ pkgs.shikaku ];

---

Submitting to nixpkgs

File layout (already correct for the PR)

pkgs/by-name/sh/shikaku/
├── package.nix    ← the derivation
└── shikaku.py     ← the game source (single file)

The pkgs/by-name directory is automatically wired into nixpkgs — no edits to all-packages.nix are needed. The package attribute pkgs.shikaku is created automatically from the directory name.

Steps before opening the PR

1. Host the source. Push this repo to GitHub (or another forge). The src.rev and src.hash in package.nix must point to a real tagged commit. Get the hash with:

   nix-prefetch-url --unpack https://github.com/YOU/shikaku/archive/v0.1.0.tar.gz
   # or with the newer tooling:
   nix store prefetch-file --hash-type sha256 --unpack \
     https://github.com/YOU/shikaku/archive/refs/tags/v0.1.0.tar.gz
   

2. Add yourself as a maintainer. Edit maintainers/maintainer-list.nix in nixpkgs to add your handle, then reference it in package.nix:

   maintainers = with lib.maintainers; [ your-handle ];
   

3. Build and run locally from the nixpkgs root:

   nix-build -A shikaku
   ./result/bin/shikaku
   

4. Check nixpkgs-vet passes (CI runs this automatically, but you can run it locally too):

   nix-build pkgs/top-level/release.nix -A tarball.nixpkgs-basic-release-checks \
     --arg supportedSystems '["x86_64-linux"]'
   

5. Open the PR with the commit message format nixpkgs expects:

   shikaku: init at 0.1.0
   

   Include in the PR description:

   • A screenshot of the game running
   • Link to the upstream source
   • Confirmation it builds on x86_64-linux (and aarch64-linux if you can)

nixpkgs reviewer checklist (pre-answered)

Requirement	Status
pkgs/by-name/sh/shikaku/package.nix	✅
pname lowercase, no spaces	✅ "shikaku"
version present	✅
Source from fetchFromGitHub with pinned rev and hash	✅ (fill in hash)
meta.description — short, no trailing period	✅
meta.license	✅ lib.licenses.mit
meta.maintainers	⚠️ add yourself
meta.homepage	⚠️ add your repo URL
meta.platforms	✅ lib.platforms.linux (GTK4, Linux only)
meta.mainProgram	✅ "shikaku"
wrapGAppsHook4 for GTK4 app	✅
gobject-introspection in nativeBuildInputs	✅
No flake.nix in the package dir	✅

---

How puzzle generation works

Puzzles are generated in reverse, guaranteeing solvability:

1. The full grid is partitioned into random non-overlapping rectangles (every cell belongs to exactly one rectangle, no gaps).
2. Each rectangle gets one randomly chosen clue cell, with the rectangle's area written as the number.
3. The player sees only the clue numbers and must reconstruct the rectangles.

Because the rectangles are generated first and clues derived from them, every puzzle is solvable by construction. There is no backtracking solver needed.

Dependencies

Dependency	Why
python3	Runtime
pygobject3	GTK4 Python bindings
gtk4	GUI toolkit
gobject-introspection	Required at build time for PyGObject
wrapGAppsHook4	Wraps binary with correct GDK/GI env vars at runtime

All managed by Nix — nothing to install manually.