Use fcitx5-anthy

fcitx5-anthy.nix

@@ -0,0 +1,26 @@
+{ lib, stdenv, fetchurl, cmake, extra-cmake-modules, pkg-config, fcitx5, anthy, gettext }:
+
+stdenv.mkDerivation rec {
+  pname = "fcitx5-anthy";
+  version = "5.0.13";
+
+  src = fetchurl {
+    url = "https://download.fcitx-im.org/fcitx5/fcitx5-anthy/${pname}-${version}.tar.xz";
+    sha256 = "EGpyYiNalm4En3Oa++hyOSPLhjbkVcDyZt3LqamfSOI=";
+  };
+
+  nativeBuildInputs = [ cmake extra-cmake-modules pkg-config ];
+  buildInputs = [ fcitx5 anthy gettext ];
+
+  preinstall = ''
+    substituteInPlace src/cmake_install.cmake \
+      --replace ${fcitx5} $out
+  '';
+
+  meta = with lib; {
+    description = "Anthy Wrapper for Fcitx5";
+    homepage = "https://github.com/fcitx/fcitx5-anthy";
+    license = licenses.gpl2Plus;
+    platforms = platforms.linux;
+  };
+}

fcitx5.nix

@@ -18,7 +18,7 @@ in
 {
   i18n.inputMethod = {
     enabled = "fcitx5";
-    fcitx5.addons = with pkgs.fcitx-engines; [ anthy ];
+    fcitx5.addons = [ (pkgs.callPackage ./fcitx5-anthy.nix {}) ];
   };
 
   home.file = {