flake.nix: build sqlite with ICU extension

flake.nix

@@ -43,7 +43,12 @@
       "armv7l-linux"
     ];
 
-    forAllSystems = f: lib.genAttrs systems (system: f system nixpkgs.legacyPackages.${system});
+    forAllSystems = f: lib.genAttrs systems (system: let
+      pkgs = import nixpkgs {
+        inherit system;
+        overlays = [ self.overlays.sqlite-icu-ext ];
+      };
+    in f system pkgs);
   in {
     apps = forAllSystems (system: pkgs: {
       default = {
@@ -102,6 +107,19 @@
       };
     });
 
+    overlays.sqlite-icu-ext = final: prev: {
+      sqlite = prev.sqlite.overrideAttrs (prev': {
+        configureFlags = prev'.configureFlags ++ [
+          "--with-icu-config=${lib.getExe' prev.icu.dev "icu-config"}"
+          "--enable-icu-collations"
+        ];
+
+        buildInputs = prev'.buildInputs ++ [
+          prev.icu
+        ];
+      });
+    };
+
     packages = let
       edrdgMetadata = {
         license = [{
@@ -135,6 +153,8 @@
         ln -s ${src} $out
       '';
 
+      inherit (pkgs) dart sqlite sqlite-interactive;
+
       jmdict = pkgs.callPackage ./nix/jmdict.nix {
         inherit jmdict-src jmdict-with-examples-src edrdgMetadata;
       };