flet: fix out of the box experience

pkgs/by-name/fl/flet-client-flutter/package.nix

@@ -0,0 +1,64 @@
+{ lib
+, fetchFromGitHub
+, pkg-config
+, flutter
+, gst_all_1
+, libunwind
+, makeWrapper
+, mimalloc
+, orc
+, nix-update-script
+, mpv-unwrapped
+, libplacebo
+}:
+
+flutter.buildFlutterApplication rec {
+  pname = "flet-client-flutter";
+  version = "0.21.1";
+
+  src = fetchFromGitHub {
+    owner = "flet-dev";
+    repo = "flet";
+    rev = "v${version}";
+    hash = "sha256-7zAcjek4iZRsNRVA85KBtU7PGbnLDZjnEO8Q5xwBiwM=";
+  };
+
+  sourceRoot = "${src.name}/client";
+
+  cmakeFlags = [
+    "-DMIMALLOC_LIB=${mimalloc}/lib/mimalloc.o"
+  ];
+
+  pubspecLock = lib.importJSON ./pubspec.lock.json;
+
+  nativeBuildInputs = [
+    makeWrapper
+    mimalloc
+    pkg-config
+  ];
+
+  buildInputs = [
+    mpv-unwrapped
+    gst_all_1.gst-libav
+    gst_all_1.gst-plugins-base
+    gst_all_1.gst-vaapi
+    gst_all_1.gstreamer
+    libunwind
+    orc
+    mimalloc
+  ]
+    ++ mpv-unwrapped.buildInputs
+    ++ libplacebo.buildInputs
+  ;
+
+  passthru.updateScript = nix-update-script { };
+
+  meta = {
+    description = "A framework that enables you to easily build realtime web, mobile, and desktop apps in Python. The frontend part";
+    homepage = "https://flet.dev/";
+    changelog = "https://github.com/flet-dev/flet/releases/tag/v${version}";
+    license = lib.licenses.asl20;
+    maintainers = with lib.maintainers; [ heyimnova lucasew ];
+    mainProgram = "flet";
+  };
+}