Fix decker derivation

derivations/decker/default.nix

@@ -3,11 +3,10 @@
   stdenv,
   fetchurl,
   autoPatchelfHook,
-  pkgs,
+  zlib,
-  gcc,
+  bzip2,
-  glib,
+  ncurses,
-  glibc,
+  gmp
-  zlib
 }:
 stdenv.mkDerivation rec {
   pname = "decker";
@@ -15,23 +14,33 @@ stdenv.mkDerivation rec {
 
   src = fetchurl {
     url = "https://github.com/decker-edu/decker/releases/download/v0.13.4/${pname}-v${version}-Linux-X64";
-    sha512 = "";
+    sha256 = "sha256-LZ0j2X0zCP9XsWglc488nL25w3VmWh/TYxK1x6K6yOI=";
   };
 
   nativeBuildInputs = [
     autoPatchelfHook
   ];
 
+  unpackCmd = ''
+    mkdir -p root
+    cp $curSrc root/decker
+  '';
+
   dontBuild = true;
 
   buildInputs = [
-    
+    stdenv.cc.cc.lib
+    zlib
+    bzip2
+    ncurses
+    gmp
   ];
 
   installPhase = ''
     runHook preInstall
-    mkdir -p $out
+    mkdir -p $out/bin
-    cp ${pname}-v${version}-Linux-X64 $out/bin/decker
+    cp decker $out/bin/decker
+    chmod +x $out/bin/decker
     runHook postInstall
   '';