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/f843fwr4b9lln1f3w6fb7wlzwlkyvlac-packages.json.drv
building '/nix/store/f843fwr4b9lln1f3w6fb7wlzwlkyvlac-packages.json.drv'...

Going to be running update for following packages:
 - buck2-unstable-2026-04-15

Press Enter key to continue...
Running update for:
Enqueuing group of 1 packages
 - buck2-unstable-2026-04-15: UPDATING ...
 - buck2-unstable-2026-04-15: 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 5738dd882710..cbf18a92f293 100644
--- a/pkgs/by-name/bu/buck2/hashes.json
+++ b/pkgs/by-name/bu/buck2/hashes.json
@@ -1,17 +1,17 @@
 {
   "aarch64-darwin": {
-    "buck2": "sha256-zBZ2gEPRxyaBYmnRfYfhYDqswqfiXvxYDHrUI92Z1UQ=",
-    "rust-project": "sha256-K86j0E32w0DUwzpPT0NBUiL3rV4Ze8hzfbKDkpy9JXo="
-  },
-  "x86_64-linux": {
-    "buck2": "sha256-IqDsyQ7Omy7QujT85oKrWwyirG7gwfupdxzvRoMRmQs=",
-    "rust-project": "sha256-iFSko4FTvAVlKUxJE/6FzR6H7V2SryRfEi7nRhfyhxQ="
+    "buck2": "sha256-CIysxyxAD6Q4vkBSw2eC9Wsq+GKHqt8T7OXpdy1yRVw=",
+    "rust-project": "sha256-o5m58wQ9zKkpa5GzgLpcLUV9LpA+n+MxVa/9hH9Tr40="
   },
   "aarch64-linux": {
-    "buck2": "sha256-VKV1vltATu3tAPmMiifba7MV9kNFH754FDda6i8cQrU=",
-    "rust-project": "sha256-oqxHdbNzQn1KHObboAd4/LTbilIJgLqMiWCgHLaPFrc="
+    "buck2": "sha256-4jm/cvQKeYfbkCTrbV4yVkL2SWxYnexr5UwQCNJhihk=",
+    "rust-project": "sha256-vGSOwVETwYqwBhkxlSTDJlVcMfbAIzYwDhEKbqz+6ok="
+  },
+  "x86_64-linux": {
+    "buck2": "sha256-7MPYB90LD+/xpCNoi9WYJjuDOdIj5oVXiocZZFbBnZU=",
+    "rust-project": "sha256-de0SbH6cbjdDhcPpDTjxBo5HgQ8yS1eokQYjQrHKIDY="
   },
-  "version": "2026-04-15",
-  "preludeGit": "f0896771c4cc1ab8f87e032c5293376c89e5096b",
-  "preludeFod": "sha256-Ga4q9zzifgFDGx0TbcbBoDN29H3A4s1BZnSwwv9Mix0="
+  "version": "2026-07-15",
+  "preludeGit": "caed0b8c0ee137c4e5e1f800a5054df151f490c2",
+  "preludeFod": "sha256-nMHnBf4vQJIxPgarmLPY38b15DFW2FlAQxDCzJgB+w8="
 }

No auto update branch exists
Old version unstable-2026-04-15" not present in master derivation file with contents: {
  "aarch64-darwin": {
    "buck2": "sha256-zBZ2gEPRxyaBYmnRfYfhYDqswqfiXvxYDHrUI92Z1UQ=",
    "rust-project": "sha256-K86j0E32w0DUwzpPT0NBUiL3rV4Ze8hzfbKDkpy9JXo="
  },
  "x86_64-linux": {
    "buck2": "sha256-IqDsyQ7Omy7QujT85oKrWwyirG7gwfupdxzvRoMRmQs=",
    "rust-project": "sha256-iFSko4FTvAVlKUxJE/6FzR6H7V2SryRfEi7nRhfyhxQ="
  },
  "aarch64-linux": {
    "buck2": "sha256-VKV1vltATu3tAPmMiifba7MV9kNFH754FDda6i8cQrU=",
    "rust-project": "sha256-oqxHdbNzQn1KHObboAd4/LTbilIJgLqMiWCgHLaPFrc="
  },
  "version": "2026-04-15",
  "preludeGit": "f0896771c4cc1ab8f87e032c5293376c89e5096b",
  "preludeFod": "sha256-Ga4q9zzifgFDGx0TbcbBoDN29H3A4s1BZnSwwv9Mix0="
}