anchor.diff:      if stdenv.platform ? kernelArch then stdenv.platform.kernelArch else
       abort "don't know what the kernel include directory is called for this platform";
   
  -  buildInputs = [perl];
  -
     extraIncludeDirs =
       if cross != null then
           (if cross.arch == "powerpc" then ["ppc"] else [])
  
positive.code: { stdenv, fetchurl, perl, cross ? null }:
  
  assert cross == null -> stdenv.isLinux;
  
  
negative.code:        export ARCH=$platform
      fi
      make ${kernelHeadersBaseConfig} SHELL=bash
    '';
  
    installPhase = ''
      make INSTALL_HDR_PATH=$out headers_install
  
      # Cleanup some unneeded files
      find $out/include \( -name .install -o -name ..install.cmd \) -delete
  
      # Some builds (e.g. KVM) want a kernel.release.
      mkdir -p $out/include/config
  