python310Packages.zxing-cpp 0 -> 1
attrpath: python310Packages.zxing-cpp
Checking auto update branch...
[version] 
[version] skipping because derivation has updateScript
[rustCrateVersion] 
[rustCrateVersion] No cargoSha256 or cargoHash found
[golangModuleVersion] 
[golangModuleVersion] Not a buildGoModule package with vendorSha256 or vendorHash
[npmDepsVersion] 
[npmDepsVersion] No npmDepsHash
[updateScript] 
[updateScript] Success
[updateScript] this derivation will be built:
  /nix/store/lgx6kjj6nk72x6m0xg1rdxixrg83z55x-packages.json.drv
building '/nix/store/lgx6kjj6nk72x6m0xg1rdxixrg83z55x-packages.json.drv'...

Going to be running update for following packages:
 - python3.10-zxing-cpp-2.1.0

Press Enter key to continue...
Running update for:
 - python3.10-zxing-cpp-2.1.0: UPDATING ...
 - python3.10-zxing-cpp-2.1.0: DONE.

Packages updated!

Diff after rewrites:
diff --git a/pkgs/development/libraries/zxing-cpp/default.nix b/pkgs/development/libraries/zxing-cpp/default.nix
index 1c010638693e..2a74fa2d8077 100644
--- a/pkgs/development/libraries/zxing-cpp/default.nix
+++ b/pkgs/development/libraries/zxing-cpp/default.nix
@@ -9,13 +9,13 @@
 
 stdenv.mkDerivation (finalAttrs: {
   pname = "zxing-cpp";
-  version = "2.1.0";
+  version = "2.2.1";
 
   src = fetchFromGitHub {
     owner = "zxing-cpp";
     repo = "zxing-cpp";
-    rev = "v${finalAttrs.version}";
-    hash = "sha256-B/jGsHImRfj0iEio2b6R6laWBI1LL3OI407O7sren8s=";
+    rev = "refs/tags/v${version}";
+    hash = "sha256-teFspdATn9M7Z1vSr/7PdJx/xAv+TVai8rIekxqpBZk=";
   };
 
   nativeBuildInputs = [

The derivation has no 'version' attribute, so do not know how to figure out the version while doing an updateScript update