Running nixpkgs-update (https://nix-community.org/update-bot/) with UPDATE_INFO: buck2 0 -> 1
attrpath: buck2
Checking auto update branch...
[version] 
[version] generic version rewriter does not support multiple hashes
[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/jxr90cj61d8diqdg9nfva6rq77b83m0d-packages.json.drv
building '/nix/store/jxr90cj61d8diqdg9nfva6rq77b83m0d-packages.json.drv'...

Going to be running update for following packages:
 - buck2-unstable-2025-12-01

Press Enter key to continue...
Running update for:
Enqueuing group of 1 packages
 - buck2-unstable-2025-12-01: UPDATING ...
 - buck2-unstable-2025-12-01: DONE.

Packages updated!

Diff after rewrites:
diff --git a/pkgs/by-name/bu/buck2/hashes.json b/pkgs/by-name/bu/buck2/hashes.json
index ced513105160..56c67e7b1778 100644
--- a/pkgs/by-name/bu/buck2/hashes.json
+++ b/pkgs/by-name/bu/buck2/hashes.json
@@ -1,21 +1,21 @@
 {
-  "x86_64-linux": {
-    "buck2": "sha256-TOgL0pLnNEAhHkKvynnM91kW06K6jZPeJnpSibYg8EU=",
-    "rust-project": "sha256-s5JY/m+yC3YNHiOxk6D43ZkWdtWLxlI4X72jSFFd3Hc="
-  },
-  "x86_64-darwin": {
-    "buck2": "sha256-8SvAZ30ZFsamVAheKpa2vzGty1TZECUv+BHeXLlDneQ=",
-    "rust-project": "sha256-0af+q1s7iEb6dWl4WuNxFbIskTfrHtU2uhatPyAhZNM="
+  "aarch64-darwin": {
+    "buck2": "sha256-X5cKLZ8xTnVdKypvxm12P9rw2dHfJzVLBIaFqqNYIto=",
+    "rust-project": "sha256-Jg+8fNidU5kFqGF9qXeNVHAlJxG0OIIta5XWOmQxzzw="
   },
   "aarch64-linux": {
-    "buck2": "sha256-Pka0HEEqRsQp2R435duy6gJy/RQXp5lK5Dg9+rfr9L8=",
-    "rust-project": "sha256-u3b+XscQpNZOo8OTrLSazFZvm496U4nsWti/6TRf8ZA="
+    "buck2": "sha256-iL7MHcgAxMr7vSkpBDiGn5/CdBFoet7wbRB9yfZhLZM=",
+    "rust-project": "sha256-KvmvlUVeB2KtIVAj4wUFMl2blVVFih28ilNcsJduxqk="
   },
-  "aarch64-darwin": {
-    "buck2": "sha256-1Fv0LzAZUN/BbcorCBaPBbm8JAzLarhJysLqPT78XEQ=",
-    "rust-project": "sha256-PQ7WKjzAPT0uRirWzwJPxKr9V1RQajnlXUMnv8SYdso="
+  "x86_64-linux": {
+    "buck2": "sha256-R1fvNuiQOxCmi9/oa8/AfQ4r47QHgGwty2tiCizDjs0=",
+    "rust-project": "sha256-hdUbUfMQjLtaei+RLKtEnmwc22s7IXOgtWaLTyAI1zo="
+  },
+  "x86_64-darwin": {
+    "buck2": "sha256-Hi1u2DQerb8K9ZfXhX2aJHCSIxfUS95AQvuTR/ZyVaU=",
+    "rust-project": "sha256-ZJkVdhjiixq3fqSevT5+cTnCry8OwYTm+RPJ5e/WM7E="
   },
-  "version": "2025-12-01",
-  "preludeGit": "0a994e0b600f7d035e1ac69f374c0e37e1e19af6",
-  "preludeFod": "sha256-IQa4VatN5OaDSyoTbAj1tHNBpJV6Ost9RbLxDD23xVQ="
+  "version": "2026-04-01",
+  "preludeGit": "8cc9fbea3ba20e3ce8b1235a1c8a4643170fb54d",
+  "preludeFod": "sha256-Csn3x6Sr1ykBpDElZvY6yJCkHNF3+G9OH6HB/2xHkRs="
 }

No auto update branch exists
Old version unstable-2025-12-01" not present in master derivation file with contents: {
  "x86_64-linux": {
    "buck2": "sha256-TOgL0pLnNEAhHkKvynnM91kW06K6jZPeJnpSibYg8EU=",
    "rust-project": "sha256-s5JY/m+yC3YNHiOxk6D43ZkWdtWLxlI4X72jSFFd3Hc="
  },
  "x86_64-darwin": {
    "buck2": "sha256-8SvAZ30ZFsamVAheKpa2vzGty1TZECUv+BHeXLlDneQ=",
    "rust-project": "sha256-0af+q1s7iEb6dWl4WuNxFbIskTfrHtU2uhatPyAhZNM="
  },
  "aarch64-linux": {
    "buck2": "sha256-Pka0HEEqRsQp2R435duy6gJy/RQXp5lK5Dg9+rfr9L8=",
    "rust-project": "sha256-u3b+XscQpNZOo8OTrLSazFZvm496U4nsWti/6TRf8ZA="
  },
  "aarch64-darwin": {
    "buck2": "sha256-1Fv0LzAZUN/BbcorCBaPBbm8JAzLarhJysLqPT78XEQ=",
    "rust-project": "sha256-PQ7WKjzAPT0uRirWzwJPxKr9V1RQajnlXUMnv8SYdso="
  },
  "version": "2025-12-01",
  "preludeGit": "0a994e0b600f7d035e1ac69f374c0e37e1e19af6",
  "preludeFod": "sha256-IQa4VatN5OaDSyoTbAj1tHNBpJV6Ost9RbLxDD23xVQ="
}