nix: initial tooling

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: Ibc12bc627f65a4b1d3430bdf8b86db256a6a6964

nix/package.nix

@@ -0,0 +1,41 @@
+{
+  lib,
+  stdenv,
+  systemdSupport ? lib.meta.availableOn stdenv.hostPlatform systemd,
+  systemd,
+}:
+stdenv.mkDerivation {
+  pname = "sin";
+  version = "0.1.0";
+
+  src = let
+    fs = lib.fileset;
+    s = ../.;
+  in
+    fs.toSource {
+      root = s;
+      fileset = fs.unions [
+        (s + /Makefile)
+        (s + /main.c)
+      ];
+    };
+
+  strictDeps = true;
+  buildInputs = lib.optionals systemdSupport [systemd];
+
+  installPhase = ''
+    runHook preInstall
+
+    mkdir -p $out/bin
+    install -Dm755 sin $out/bin/sin
+
+    runHook postInstall
+  '';
+
+  meta = {
+    description = "Keep system idle inhibited while named processes run";
+    license = lib.licenses.mit;
+    maintainers = [lib.maintainers.NotAShelf];
+    platforms = lib.platforms.linux;
+  };
+}