Attempt fix with autoelfpatch

packages/linuxcnc-ethercat/default.nix

@@ -13,17 +13,28 @@ stdenv.mkDerivation rec {
     sha256 = "SjFkcNl/4AlsMeIw5Hg9Kp5mIIV9KFUYodXV6lAi3/A=";
   };
 
-  nativeBuildInputs = with pkgs; [ which expat ];
+  nativeBuildInputs = with pkgs; [
+    autoPatchelfHook
+    which
+    expat
+  ];
 
   buildInputs = [ linuxcnc ethercat ];
 
+  preBuild = ''
+    #addAutoPatchelfSearchPath ${placeholder "out"}/lib/linuxcnc/modules/
+  '';
+
   installFlags = [
+    "prefix=${placeholder "out"}"
+    #"RUN_IN_PLACE=YES"
     "DESTDIR=${placeholder "out"}"
     "EMC2_HOME=''"
     "LIBDIR=''"
     "RTLIBDIR='/lib/linuxcnc/modules'"
   ];
 
+
   meta = with lib; {
     description = "LinuxCNC ethercat interop";
     platforms = platforms.linux;