Let's see if I can build cinny from source

pkgs/cinny/default.nix

@@ -0,0 +1,50 @@
+{
+  lib,
+  buildNpmPackage,
+  fetchFromGitHub,
+  pkgs,
+}: let
+  port = 2143;
+  configFile =
+    pkgs.writeText "config.json"
+    ''
+      {
+          "defaultHomeserver": 0,
+          "homeserverList": [
+              "matrix.gladtherescake.eu"
+          ],
+          "allowCustomHomeservers": false
+      }
+    '';
+in
+  buildNpmPackage rec {
+    pname = "cinny";
+    version = "09a0a2d";
+
+    src = fetchFromGitHub {
+      owner = "cinnyapp";
+      repo = pname;
+      rev = "${version}";
+      hash = "sha256-ee8YOJ0fGy26OWXb2Uumzy68M4UpERHH3ni0q+tDY14=";
+    };
+
+    npmDepsHash = "sha256-zelk15/rXXjhWuHj1GsSevnyXVBeDkMJ0qZfPyejq4A=";
+
+    # The prepack script runs the build script, which we'd rather do in the build phase.
+    npmPackFlags = ["--ignore-scripts" "--max_old_space_size=4096"];
+
+    installPhase = ''
+      mkdir $out
+      npm run build
+      cp -r dist/* $out
+      mkdir $out/app
+      cp ${configFile} $out/app/config.json
+    '';
+
+    meta = with lib; {
+      description = "Yet another matrix client";
+      homepage = "https://cinny.in/";
+      license = licenses.agpl3O;
+      maintainers = with maintainers; [Lillian-Violet];
+    };
+  }