Running nixpkgs-update (https://nix-community.org/update-bot/) with UPDATE_INFO: asmrepl 0 -> 1
attrpath: asmrepl
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] 
Going to be running update for following packages:
 - asmrepl-1.0.3

Press Enter key to continue...
Running update for:
Enqueuing group of 1 packages
 - asmrepl-1.0.3: UPDATING ...
 - asmrepl-1.0.3: DONE.

Packages updated!

Diff after rewrites:
diff --git a/pkgs/development/interpreters/asmrepl/Gemfile.lock b/pkgs/development/interpreters/asmrepl/Gemfile.lock
index f845e91b6c90..f38c778b1a49 100644
--- a/pkgs/development/interpreters/asmrepl/Gemfile.lock
+++ b/pkgs/development/interpreters/asmrepl/Gemfile.lock
@@ -4,9 +4,9 @@ GEM
 GEM
   remote: https://rubygems.org/
   specs:
-    asmrepl (1.0.3)
-      fisk (~> 2)
-    fisk (2.3.0)
+    asmrepl (1.2.0)
+      fisk (~> 2.3.1)
+    fisk (2.3.2)
 
 PLATFORMS
   ruby
@@ -15,4 +15,4 @@ DEPENDENCIES
   asmrepl!
 
 BUNDLED WITH
-   2.2.24
+   2.7.2
diff --git a/pkgs/development/interpreters/asmrepl/gemset.nix b/pkgs/development/interpreters/asmrepl/gemset.nix
index f3455e515023..9959ec2fc000 100644
--- a/pkgs/development/interpreters/asmrepl/gemset.nix
+++ b/pkgs/development/interpreters/asmrepl/gemset.nix
@@ -5,19 +5,19 @@
     platforms = [ ];
     source = {
       remotes = [ "https://rubygems.org" ];
-      sha256 = "10d0zvkhk3ja48vvx28hfsqfrzfl66vdpmk3gcgb5viy174c72v6";
+      sha256 = "0qvkqn34ldlip2yz3kdckqmvniyydswcclwdcalcpdwnahg25xjw";
       type = "gem";
     };
-    version = "1.0.3";
+    version = "1.2.0";
   };
   fisk = {
     groups = [ "default" ];
     platforms = [ ];
     source = {
       remotes = [ "https://rubygems.org" ];
-      sha256 = "1mq2a7hjs9xfg514ci0xw90c33rzq1y58ywpnmhp7w767ll6wldd";
+      sha256 = "0zypl29fpqd5pqkp8j67xnq9b2dwhl8kn01fyw1kxy9l2676dlmh";
       type = "gem";
     };
-    version = "2.3.0";
+    version = "2.3.2";
   };
 }

No auto update branch exists
Old version 1.0.3" not present in master derivation file with contents: {
  lib,
  bundlerApp,
  bundlerUpdateScript,
}:

bundlerApp {
  pname = "asmrepl";
  gemdir = ./.;
  exes = [ "asmrepl" ];

  passthru.updateScript = bundlerUpdateScript "asmrepl";

  meta = {
    description = "REPL for x86-64 assembly language";
    homepage = "https://github.com/tenderlove/asmrepl";
    license = lib.licenses.asl20;
    maintainers = [ ];
    platforms = lib.platforms.x86_64;
  };
}