stdenv.mkDerivation: Support argument being a fixed-point function (self: { … }) instead of rec { … }

pkgs/applications/misc/hello/default.nix

@@ -1,11 +1,11 @@
 { stdenv, fetchurl }:
 
-stdenv.mkDerivation rec {
+stdenv.mkDerivation (self: {
   pname = "hello";
   version = "2.10";
 
   src = fetchurl {
-    url = "mirror://gnu/hello/${pname}-${version}.tar.gz";
+    url = "mirror://gnu/hello/${self.pname}-${self.version}.tar.gz";
     sha256 = "0ssi1wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i";
   };
 
@@ -18,9 +18,9 @@ stdenv.mkDerivation rec {
       It is fully customizable.
     '';
     homepage = "https://www.gnu.org/software/hello/manual/";
-    changelog = "https://git.savannah.gnu.org/cgit/hello.git/plain/NEWS?h=v${version}";
+    changelog = "https://git.savannah.gnu.org/cgit/hello.git/plain/NEWS?h=v${self.version}";
     license = licenses.gpl3Plus;
     maintainers = [ maintainers.eelco ];
     platforms = platforms.all;
   };
-}
+})

pkgs/stdenv/adapters.nix

@@ -42,9 +42,9 @@ rec {
     { mkDerivation = args:
       if stdenv'.hostPlatform.isDarwin
       then throw "Cannot build fully static binaries on Darwin/macOS"
-      else stdenv'.mkDerivation (args // {
-        NIX_CFLAGS_LINK = toString (args.NIX_CFLAGS_LINK or "") + " -static";
-        configureFlags = (args.configureFlags or []) ++ [
+      else (stdenv'.mkDerivation args).overrideAttrs (super: {
+        NIX_CFLAGS_LINK = toString (super.NIX_CFLAGS_LINK or "") + " -static";
+        configureFlags = (super.configureFlags or []) ++ [
             "--disable-shared" # brrr...
           ];
       });
@@ -54,14 +54,14 @@ rec {
   # Return a modified stdenv that builds static libraries instead of
   # shared libraries.
   makeStaticLibraries = stdenv: stdenv //
-    { mkDerivation = args: stdenv.mkDerivation (args // {
+    { mkDerivation = args: (stdenv.mkDerivation args).overrideAttrs (super: {
         dontDisableStatic = true;
-        configureFlags = (args.configureFlags or []) ++ [
+        configureFlags = (super.configureFlags or []) ++ [
           "--enable-static"
           "--disable-shared"
         ];
-        cmakeFlags = (args.cmakeFlags or []) ++ [ "-DBUILD_SHARED_LIBS:BOOL=OFF" ];
-        mesonFlags = (args.mesonFlags or []) ++ [ "-Ddefault_library=static" ];
+        cmakeFlags = (super.cmakeFlags or []) ++ [ "-DBUILD_SHARED_LIBS:BOOL=OFF" ];
+        mesonFlags = (super.mesonFlags or []) ++ [ "-Ddefault_library=static" ];
       });
     };
 
@@ -70,8 +70,8 @@ rec {
      consuming derivations
   */
   propagateBuildInputs = stdenv: stdenv //
-    { mkDerivation = args: stdenv.mkDerivation (args // {
-        propagatedBuildInputs = (args.propagatedBuildInputs or []) ++ (args.buildInputs or []);
+    { mkDerivation = args: (stdenv.mkDerivation args).overrideAttrs (super: {
+        propagatedBuildInputs = (super.propagatedBuildInputs or []) ++ (super.buildInputs or []);
         buildInputs = [];
       });
     };
@@ -87,7 +87,7 @@ rec {
            stdenv;
   */
   addAttrsToDerivation = extraAttrs: stdenv: stdenv //
-    { mkDerivation = args: stdenv.mkDerivation (args // extraAttrs); };
+    { mkDerivation = args: (stdenv.mkDerivation args).overrideAttrs (_: extraAttrs); };
 
 
   /* Return a modified stdenv that builds packages with GCC's coverage
@@ -181,17 +181,17 @@ rec {
      binaries have debug info, and compiler optimisations are
      disabled. */
   keepDebugInfo = stdenv: stdenv //
-    { mkDerivation = args: stdenv.mkDerivation (args // {
+    { mkDerivation = args: (stdenv.mkDerivation args).overrideAttrs (super: {
         dontStrip = true;
-        NIX_CFLAGS_COMPILE = toString (args.NIX_CFLAGS_COMPILE or "") + " -ggdb -Og";
+        NIX_CFLAGS_COMPILE = toString (super.NIX_CFLAGS_COMPILE or "") + " -ggdb -Og";
       });
     };
 
 
   /* Modify a stdenv so that it uses the Gold linker. */
   useGoldLinker = stdenv: stdenv //
-    { mkDerivation = args: stdenv.mkDerivation (args // {
-        NIX_CFLAGS_LINK = toString (args.NIX_CFLAGS_LINK or "") + " -fuse-ld=gold";
+    { mkDerivation = args: (stdenv.mkDerivation args).overrideAttrs (super: {
+        NIX_CFLAGS_LINK = toString (super.NIX_CFLAGS_LINK or "") + " -fuse-ld=gold";
       });
     };
 
@@ -201,8 +201,8 @@ rec {
 
      WARNING: this breaks purity! */
   impureUseNativeOptimizations = stdenv: stdenv //
-    { mkDerivation = args: stdenv.mkDerivation (args // {
-        NIX_CFLAGS_COMPILE = toString (args.NIX_CFLAGS_COMPILE or "") + " -march=native";
+    { mkDerivation = args: (stdenv.mkDerivation args).overrideAttrs (super: {
+        NIX_CFLAGS_COMPILE = toString (super.NIX_CFLAGS_COMPILE or "") + " -march=native";
         NIX_ENFORCE_NO_NATIVE = false;
 
         preferLocalBuild = true;

pkgs/stdenv/generic/make-derivation.nix

@@ -7,7 +7,7 @@ let
     # to build it. This is a bit confusing for cross compilation.
     inherit (stdenv) hostPlatform;
   };
-in rec {
+
   # `mkDerivation` wraps the builtin `derivation` function to
   # produce derivations that use this stdenv and its shell.
   #
@@ -18,7 +18,7 @@ in rec {
   #
   # * https://nixos.org/nix/manual/#ssec-derivation
   #   Explanation about derivations in general
-  mkDerivation =
+  mkDerivation' =
     {
 
     # These types of dependencies are all exhaustively documented in
@@ -90,6 +90,9 @@ in rec {
     , patches ? []
 
     , ... } @ attrs:
+    # overrideAttrs needs access to the pre-evaluation attrs arg if it's a fixed-point function.
+    # since our caller evaluates that for us, it gets to provide overrideAttrs too.
+    overrideAttrs:
 
     let
       # TODO(@oxij, @Ericson2314): This is here to keep the old semantics, remove when
@@ -336,13 +339,28 @@ in rec {
       lib.extendDerivation
         validity.handled
         ({
-           overrideAttrs = f: mkDerivation (attrs // (f attrs));
-           inherit meta passthru;
+           inherit meta overrideAttrs passthru;
          } //
          # Pass through extra attributes that are not inputs, but
          # should be made available to Nix expressions using the
          # derivation (e.g., in assertions).
          passthru)
         (derivation derivationArg);
 
+in rec {
+  # Allow `mkDerivation` to take either an attrset directly, or a fixed-point function that has a
+  # `self:` argument. The latter avoids the issues with using `rec { … }` and `overrideAttrs`.
+  mkDerivation =
+    attrs:
+    let
+      attrFun = if lib.isFunction attrs then attrs else (_: attrs);
+      overrideAttrs = f: mkDerivation (self:
+        let
+          super = attrFun self;
+          f' = f super;
+          feval = if lib.isFunction f'
+            then f self super # it's a new-style `self: super:` function
+            else f'; # it's an old-style `super:` function
+        in super // feval);
+    in mkDerivation' (lib.fix attrFun) overrideAttrs;
 }