linux/manual-config: Cleanup

pkgs/os-specific/linux/kernel/manual-config.nix

@@ -80,15 +80,16 @@ let
   ++ optional installsFirmware "INSTALL_FW_PATH=$(out)/lib/firmware";
 in
 
-let self = stdenv.mkDerivation {
+stdenv.mkDerivation {
   name = "linux-${version}";
 
   enableParallelBuilding = true;
 
   passthru = {
     inherit version modDirVersion config kernelPatches src;
+  };
 
-    source = stdenv.mkDerivation {
+  sourceRoot = stdenv.mkDerivation {
     name = "linux-${version}-source";
 
     inherit src;
@@ -110,21 +111,17 @@ let self = stdenv.mkDerivation {
       mv $sourceRoot $out
     '';
   };
-  };
 
   unpackPhase = ''
-    export sourceRoot="${self.source}"
     mkdir build
     export buildRoot="$(pwd)/build"
+    ln -sv ${configfile} $buildRoot/.config
     cd $sourceRoot
   '';
 
   configurePhase = ''
     runHook preConfigure
-    make $makeFlags "''${makeFlagsArray[@]}" mrproper
-    ln -sv ${configfile} $buildRoot/.config
     make $makeFlags "''${makeFlagsArray[@]}" oldconfig
-    rm $buildRoot/.config.old
     runHook postConfigure
   '';
 
@@ -146,7 +143,6 @@ let self = stdenv.mkDerivation {
     make modules_install $makeFlags "''${makeFlagsArray[@]}" \
       $installFlags "''${installFlagsArray[@]}"
     rm -f $out/lib/modules/${modDirVersion}/build
-    cd $buildRoot/..
     mv $buildRoot $out/lib/modules/${modDirVersion}/build
   '' else optionalString installsFirmware ''
     make firmware_install $makeFlags "''${makeFlagsArray[@]}" \
@@ -168,4 +164,4 @@ let self = stdenv.mkDerivation {
     ];
     platforms = lib.platforms.linux;
   };
-}; in self
+}