Make it work

default.nix

@@ -0,0 +1,50 @@
+{ lib
+, stdenvNoCC
+, fetchzip
+, buildFHSEnv
+}:
+
+let
+  package = stdenvNoCC.mkDerivation rec {
+    pname = "CoolTerm";
+    version = "2.1.1";
+
+    src = fetchzip {
+      url = "https://freeware.the-meiers.org/previous/CoolTermLinux64Bit${builtins.replaceStrings ["."] [""] version}.zip";
+      sha256 = "sha256-ly01SivP0gghEfNT1SvexOB5Zumo/cwiNtkirkG+ncU=";
+    };
+
+    buildCommand = ''
+      mkdir -p $out/opt/
+      cp -r $src $out/opt/CoolTerm
+    '';
+
+    meta = with lib; {
+      description = "";
+      longDescription = ''
+      '';
+      homepage = "https://freeware.the-meiers.org/";
+      sourceProvenance = with sourceTypes; [ binaryNativeCode ];
+      license = licenses.unfree;
+      maintainers = with maintainers; [ mlaga97 ];
+      platforms = [ "x86_64-linux" ];
+    };
+  };
+in
+  
+buildFHSEnv {
+  inherit (package) pname meta;
+  runScript = "${package.outPath}/opt/CoolTerm/CoolTerm";
+  targetPkgs = pkgs: (with pkgs; [
+    libgcc
+    cairo
+    gtk3
+    libunwind
+    pango
+    atk
+    gtkd
+    glib
+    gdk-pixbuf
+    xorg.libX11
+  ]);
+}

flake.nix

@@ -1,54 +0,0 @@
-{
-  description = "Test";
-
-  inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs";
-  };
-
-  outputs = { self, nixpkgs }: {
-    defaultPackage.x86_64-linux = with import nixpkgs {
-      system = "x86_64-linux";
-    }; stdenv.mkDerivation rec {
-      name = "coolterm";
-      version = "2.1.1";
-
-      src = pkgs.fetchzip {
-        url = "https://freeware.the-meiers.org/previous/CoolTermLinux64Bit211.zip";
-        sha256 = "sha256-ly01SivP0gghEfNT1SvexOB5Zumo/cwiNtkirkG+ncU=";
-      };
-
-      nativeBuildInputs = [
-        autoPatchelfHook
-      ];
-
-      buildInputs = [
-        libgcc
-        cairo
-        gtk3
-        libunwind
-      ];
-
-      sourceRoot = ".";
-
-      installPhase = ''
-        runHook preInstall
-
-        mkdir -p $out/opt/
-        cp -r ./source/* $out/opt/
-
-        for i in `ls -1 "./source/CoolTerm Libs/"`; do
-          install -m755 -D "./source/CoolTerm Libs/$i" $out/lib/$i
-        done
-        install -m755 -D "./source/CoolTerm" $out/bin/CoolTerm
-
-        runHook postInstall
-      '';
-
-      meta = with lib; {
-        homepage = "https://freeware.the-meiers.org/";
-        description = "CoolTerm";
-        platforms = platforms.linux;
-      };
-    };
-  };
-}