fix tar command

pkgs/microcosm/default.nix

···
     nativeBuildInputs = nativeInputs;
     buildInputs = buildInputs;
     env = commonEnv;
+    overrideVendorCargoPackage = pkg: drv:
+      if pkg.name == "cfg-if" then
+        drv.overrideAttrs (old: {
+          unpackPhase = ''
+            tar -xzf $src --no-same-owner
+          '';
+          requiredSystemFeatures = [ "local-build" ];
+        })
+      else
+        drv;
   };
 
   members = [