Running nixpkgs-update (https://nix-community.org/update-bot/) with UPDATE_INFO: flatcc 0.6.3 -> 0.6.4 https://github.com/dvidelabs/flatcc/releases
attrpath: flatcc
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/f7a5l4dsyy5nbphf3s2hm4r5mwgladr0-packages.json.drv
building '/nix/store/f7a5l4dsyy5nbphf3s2hm4r5mwgladr0-packages.json.drv'...
structuredAttrs is enabled

Going to be running update for following packages:
 - flatcc-0.6.3

Press Enter key to continue...
Running update for:
Enqueuing group of 1 packages
 - flatcc-0.6.3: UPDATING ...
 - flatcc-0.6.3: DONE.

Packages updated!

Diff after rewrites:
diff --git a/pkgs/by-name/fl/flatcc/package.nix b/pkgs/by-name/fl/flatcc/package.nix
index e32eca7c4102..de89791f205e 100644
--- a/pkgs/by-name/fl/flatcc/package.nix
+++ b/pkgs/by-name/fl/flatcc/package.nix
@@ -9,7 +9,7 @@
 
 stdenv.mkDerivation (finalAttrs: {
   pname = "flatcc";
-  version = "0.6.3";
+  version = "0.6.4";
 
   __structuredAttrs = true;
   strictDeps = true;
@@ -18,7 +18,7 @@ stdenv.mkDerivation (finalAttrs: {
     owner = "dvidelabs";
     repo = "flatcc";
     tag = "v${finalAttrs.version}";
-    hash = "sha256-kDZ05r/k15peBLGG2jzyeKwrdTn3+1PWrrDUmC3SV50=";
+    hash = "sha256-J3vw7DYhaYD7QVChcNElKCYoh0cwGJj2hr5ugcIcZZw=";
   };
 
   nativeBuildInputs = [ cmake ];

No auto update branch exists
There might already be an open PR for this update:
- flatcc: 0.6.3 -> 0.6.4
  URL "https://api.github.com/repos/NixOS/nixpkgs/issues/566429"