diff --git a/pkgs/by-name/li/libcollectdclient/package.nix b/pkgs/by-name/li/libcollectdclient/package.nix
index ae8b2dc671fc..b9247629c574 100644
--- a/pkgs/by-name/li/libcollectdclient/package.nix
+++ b/pkgs/by-name/li/libcollectdclient/package.nix
@@ -2,7 +2,6 @@
 
 collectd.overrideAttrs (oldAttrs: {
   pname = "libcollectdclient";
-  inherit (collectd) version;
   buildInputs = [ ];
 
   configureFlags = (oldAttrs.configureFlags or [ ]) ++ [
diff --git a/pkgs/stdenv/darwin/default.nix b/pkgs/stdenv/darwin/default.nix
index 00ce52edd947..49f0ff040a41 100644
--- a/pkgs/stdenv/darwin/default.nix
+++ b/pkgs/stdenv/darwin/default.nix
@@ -439,6 +439,7 @@ assert bootstrapTools.passthru.isFromBootstrapFiles or false; # sanity check
               (superDarwin.binutils-unwrapped.override { enableManpages = false; }).overrideAttrs
                 (old: {
                   version = "boot";
+                  __intentionallyOverridingVersion = true; # to avoid a warning suggesting to provide src
                   passthru = (old.passthru or { }) // {
                     isFromBootstrapFiles = true;
                   };
diff --git a/pkgs/stdenv/generic/make-derivation.nix b/pkgs/stdenv/generic/make-derivation.nix
index 499602a94448..7bd3301169c9 100644
--- a/pkgs/stdenv/generic/make-derivation.nix
+++ b/pkgs/stdenv/generic/make-derivation.nix
@@ -36,6 +36,7 @@ let
     remove
     splitString
     subtractLists
+    toFunction
     unique
     zipAttrsWith
     ;
@@ -61,12 +62,7 @@ let
     Most arguments are also passed through to the underlying call of [`builtins.derivation`](https://nixos.org/manual/nix/stable/language/derivations).
     :::
   */
-  mkDerivation =
-    fnOrAttrs:
-    if builtins.isFunction fnOrAttrs then
-      makeDerivationExtensible fnOrAttrs
-    else
-      makeDerivationExtensibleConst fnOrAttrs;
+  mkDerivation = fnOrAttrs: makeDerivationExtensible (toFunction fnOrAttrs);
 
   checkMeta = import ./check-meta.nix {
     inherit lib config;
@@ -99,6 +95,10 @@ let
                 thisOverlay = overlay final prev;
                 warnForBadVersionOverride = (
                   thisOverlay ? version
+                  && prev ? version
+                  # We could check that the version is actually distinct, but that
+                  # would probably just delay the inevitable, or preserve tech debt.
+                  # && prev.version != thisOverlay.version
                   && !(thisOverlay ? src)
                   && !(thisOverlay.__intentionallyOverridingVersion or false)
                 );
@@ -135,25 +135,6 @@ let
     in
     finalPackage;
 
-  #makeDerivationExtensibleConst = attrs: makeDerivationExtensible (_: attrs);
-  # but pre-evaluated for a slight improvement in performance.
-  makeDerivationExtensibleConst =
-    attrs:
-    mkDerivationSimple (
-      f0:
-      let
-        f =
-          self: super:
-          let
-            x = f0 super;
-          in
-          if builtins.isFunction x then f0 self super else x;
-      in
-      makeDerivationExtensible (
-        self: attrs // (if builtins.isFunction f0 || f0 ? __functor then f self attrs else f0)
-      )
-    ) attrs;
-
   knownHardeningFlags = [
     "bindnow"
     "format"
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 65191596e7f9..c6d576b89c01 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -15911,6 +15911,7 @@ with pkgs;
     polyml = polyml.overrideAttrs {
       pname = "polyml-for-isabelle";
       version = "2025";
+      __intentionallyOverridingVersion = true; # avoid a warning, no src override
       configureFlags = [
         "--enable-intinf-as-int"
         "--with-gmp"