nix: use trexio as flake

flake.nix

@@ -10,10 +10,7 @@
 
     nixpkgs.url = "github:NixOS/nixpkgs";
 
-    trexio = {
-      url = "github:TREX-CoE/trexio";
-      flake = false;
-    };
+    trexio.url = "github:TREX-CoE/trexio";
   };
 
   outputs =
@@ -24,16 +21,14 @@
       flake-utils,
     }:
     let
-      trexioOvl = import ./nix/overlay.nix {
-        trexioSrc = trexio;
-      };
+      trexioOvl = import ./nix/overlay.nix;
     in
     flake-utils.lib.eachDefaultSystem (
       system:
       let
         pkgs = import nixpkgs {
           inherit system;
-          overlays = [ trexioOvl ];
+          overlays = [ /*trexio.overlays.default*/ trexioOvl ];
         };
       in
       {

nix/overlay.nix

@@ -1,31 +1,14 @@
-{ trexioSrc }:
 final: prev: {
-  trexio = prev.trexio.overrideAttrs (oldAttrs: {
-    src = prev.lib.cleanSourceWith {
-      src = trexioSrc;
-      filter =
-        path: type:
-        !(
-          builtins.elem (builtins.baseNameOf path) [
-            "docker"
-            "helpers-debian"
-            "ocaml"
-            "rust"
-          ]
-          && type == "directory"
-        );
-    };
-  });
-
-  haskell = prev.haskell // 
-  {
-    packageOverrides = hfinal: hprev: 
-    let ghcMajor = prev.lib.versions.major hprev.ghc.version;
+  haskell = prev.haskell // {
+    packageOverrides =
+      hfinal: hprev:
+      let
+        ghcMajor = prev.lib.versions.major hprev.ghc.version;
         ghcMinor = prev.lib.versions.minor hprev.ghc.version;
-    in prev.haskell.packageOverrides hfinal hprev // {
-      trexio-hs = hfinal.callCabal2nix "trexio-hs" ../. { inherit (final) trexio; };
-      # template-haskell = hprev.template-haskell_2_22_0_0;
-    } // prev.lib.attrsets.optionalAttrs (ghcMajor == "9" && ghcMinor == "4") {
-    };
+      in
+      prev.haskell.packageOverrides hfinal hprev
+      // {
+        trexio-hs = hfinal.callCabal2nix "trexio-hs" ../. { inherit (final) trexio; };
+      };
   };
 }