Running nixpkgs-update (https://nix-community.org/update-bot/) with UPDATE_INFO: cddlc 0 -> 1
attrpath: cddlc
Checking auto update branch...
[version] 
[version] skipping because derivation has updateScript
[rustCrateVersion] 
[rustCrateVersion] No cargoHash found
[golangModuleVersion] 
[golangModuleVersion] Not a buildGoModule package with vendorHash
[npmDepsVersion] 
[npmDepsVersion] No npmDepsHash
[updateScript] 
[updateScript] Success
[updateScript] this derivation will be built:
  /nix/store/pp57iywpi6cfdwgagbyf1dkidcp0na18-packages.json.drv
building '/nix/store/pp57iywpi6cfdwgagbyf1dkidcp0na18-packages.json.drv'...

Going to be running update for following packages:
 - cddlc-0.4.2

Press Enter key to continue...
Running update for:
Enqueuing group of 1 packages
 - cddlc-0.4.2: UPDATING ...
 - cddlc-0.4.2: DONE.

Packages updated!

Diff after rewrites:
diff --git a/pkgs/by-name/cd/cddlc/Gemfile.lock b/pkgs/by-name/cd/cddlc/Gemfile.lock
index c3555056711f..dd54a650c444 100644
--- a/pkgs/by-name/cd/cddlc/Gemfile.lock
+++ b/pkgs/by-name/cd/cddlc/Gemfile.lock
@@ -1,12 +1,12 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    cddlc (0.4.2)
+    cddlc (0.4.3)
       neatjson (~> 0.10)
       treetop (~> 1)
     neatjson (0.10.5)
     polyglot (0.3.5)
-    treetop (1.6.14)
+    treetop (1.6.18)
       polyglot (~> 0.3)
 
 PLATFORMS
@@ -16,4 +16,4 @@ DEPENDENCIES
   cddlc
 
 BUNDLED WITH
-   2.6.9
+   2.7.2
diff --git a/pkgs/by-name/cd/cddlc/gemset.nix b/pkgs/by-name/cd/cddlc/gemset.nix
index 997b4c7cabcf..8d76bc191eb7 100644
--- a/pkgs/by-name/cd/cddlc/gemset.nix
+++ b/pkgs/by-name/cd/cddlc/gemset.nix
@@ -8,10 +8,10 @@
     platforms = [ ];
     source = {
       remotes = [ "https://rubygems.org" ];
-      sha256 = "1s3fbgd5yqgji162zsmlwnva1v1r3zc1qiyv6im7karv5f08r8m3";
+      sha256 = "1v5c40556faf2kxk8pd9azl5ciiaa52pw7qmdp43zimk3hnnbxna";
       type = "gem";
     };
-    version = "0.4.2";
+    version = "0.4.3";
   };
   neatjson = {
     groups = [ "default" ];
@@ -39,9 +39,9 @@
     platforms = [ ];
     source = {
       remotes = [ "https://rubygems.org" ];
-      sha256 = "1m5fqy7vq6y7bgxmw7jmk7y6pla83m16p7lb41lbqgg53j8x2cds";
+      sha256 = "1nl3q5ai7ikaa5sjdbspfa4njbrdvf7898zkplmalln6y4r3y153";
       type = "gem";
     };
-    version = "1.6.14";
+    version = "1.6.18";
   };
 }

No auto update branch exists
Old version 0.4.2" not present in master derivation file with contents: {
  lib,
  bundlerApp,
  bundlerUpdateScript,
}:

bundlerApp {
  pname = "cddlc";

  gemdir = ./.;

  exes = [ "cddlc" ];

  passthru.updateScript = bundlerUpdateScript "cddlc";

  meta = {
    description = "CDDL conversion utilities";
    homepage = "https://github.com/cabo/cddlc";
    license = lib.licenses.mit;
    maintainers = with lib.maintainers; [ amesgen ];
    platforms = lib.platforms.unix;
    mainProgram = "cddlc";
  };
}