p4est-dbg unstable-2021-06-22 -> 2.8.6 https://github.com/cburstedde/p4est/releases
attrpath: p4est-dbg
Checking auto update branch...
No auto update branch exists
[version] 
[version] updated version and sha256
[rustCrateVersion] 
[rustCrateVersion] No cargoSha256 or cargoHash found
[golangModuleVersion] 
[golangModuleVersion] Not a buildGoModule package with vendorSha256 or vendorHash
[npmDepsVersion] 
[npmDepsVersion] No npmDepsHash
[updateScript] 
[updateScript] skipping because derivation has no updateScript
Diff after rewrites:
diff --git a/pkgs/development/libraries/science/math/p4est/default.nix b/pkgs/development/libraries/science/math/p4est/default.nix
index 1218c695590e..631fab745bd0 100644
--- a/pkgs/development/libraries/science/math/p4est/default.nix
+++ b/pkgs/development/libraries/science/math/p4est/default.nix
@@ -14,14 +14,14 @@ let
 in
 stdenv.mkDerivation {
   pname = "p4est${dbg}";
-  version = "unstable-2021-06-22";
+  version = "2.8.6";
 
   # fetch an untagged snapshot of the prev3-develop branch
   src = fetchFromGitHub {
     owner = "cburstedde";
     repo = "p4est";
     rev = "7423ac5f2b2b64490a7a92e5ddcbd251053c4dee";
-    sha256 = "0vffnf48rzw6d0as4c3x1f31b4kapmdzr1hfj5rz5ngah72gqrph";
+    sha256 = "sha256-8Gb8xIHq2fJzkQ6G/Fu9apIVhgt9MKIVaIb/jIizzm0=";
   };
 
   strictDeps = true;

Source url did not change.