install fennel from source as a package

nixos lua packaging is giving me a headache

pkgs/default.nix

@@ -56,4 +56,5 @@
   firewallgen  = callPackage ./firewallgen {};
   kernel-modules  = callPackage ./kernel-modules {};
   odhcp-script = callPackage ./odhcp-script {};
+  fennel = callPackage ./fennel {};
 }

pkgs/fennel/default.nix

@@ -0,0 +1,19 @@
+{
+  stdenv
+, lua
+, fetchFromSourcehut
+}:
+let pname =  "fennel";
+in stdenv.mkDerivation {
+  inherit pname;
+  version = "1.3";
+  nativeBuildInputs = [ lua ];  # used in build
+  buildInputs = [ lua ];        # needed for patchShebangs
+  src = fetchFromSourcehut {
+    owner = "~technomancy";
+    repo = pname;
+    rev = "1.3.0";
+    hash = "sha256-DXJOdYzfjTncqL7BsDbdvZcauDMkZV2X0U0FfhfwQrw=";
+  };
+  makeFlags = [ "PREFIX=${placeholder "out"}" ];
+}

pkgs/write-fennel-script/default.nix

@@ -1,31 +1,27 @@
 {
-  runCommand
-, lua
-, runtimeShell
-, fetchurl
+  lua
 , lib
-, lua53Packages
+, fennel
+, stdenv
 }:
-let inherit (lua53Packages) lua;
-in name : packages : source :
+name : packages : source :
   let
-    fennel = fetchurl {
-      url = "https://fennel-lang.org/downloads/fennel-1.3.0";
-      hash = "sha256-hYSD3rBYF8iTjBOA1m+TvUu8BSp8q6uIMUXi0xwo/dU=";
-    };
-
     luapath = builtins.map (f: "${f}/share/lua/${lua.luaversion}/?.lua;") packages;
     luacpath = builtins.map (f: "${f}/lib/lua/${lua.luaversion}/?.so;") packages;
-  in runCommand name {
-    nativeBuildInputs =  [ lua ];
-  } ''
-     echo $PATH
-      #!${runtimeShell}
+  in stdenv.mkDerivation {
+    inherit name;
+    src = ./.;
+    nativeBuildInputs = [ fennel ];
+    buildPhase = ''
       (
        echo "#!${lua}/bin/lua"
        echo "package.path = ${lib.strings.escapeShellArg luapath} .. package.path"
        echo "package.cpath = ${lib.strings.escapeShellArg luacpath} .. package.cpath"
-      lua ${fennel} --correlate --compile ${source}
-      ) > $out
-      chmod a+x $out
-    ''
+       fennel --correlate --compile ${source}
+      ) >  ${name}.lua
+    '';
+    installPhase = ''
+      cp ${name}.lua $out
+      chmod +x $out
+    '';
+  }