nix: get nftables from correct parent attr

nix: what do you mean `baseNameOf` is not in lib

nix: `pkgs.system` -> `pkgs.hostPlatform.system`

nix: include contrib in pacakge source

nix: fix types

nix/package.nix

@@ -18,6 +18,7 @@ in
         root = s;
         fileset = fs.unions [
           (fs.fileFilter (file: builtins.any file.hasExt ["rs"]) (s + /src))
+          (s + /contrib)
           lockfile
           cargoToml
         ];
@@ -25,8 +26,8 @@ in
 
     postInstall = ''
       mkdir -p $out/share/contrib
-      cp -r ${../contrib}/corpus $out/share/contrib/
-      cp -r ${../contrib}/lua $out/share/contrib/
+      cp -rv $src/contrib/corpus $out/share/contrib
+      cp -rv $src/contrib/lua $out/share/contrib
     '';
 
     cargoLock.lockFile = lockfile;