anchor.diff:  
       installPhase = ''
         make headers_install INSTALL_HDR_PATH=$out $makeFlags
  -
  -      # Some builds (e.g. KVM) want a kernel.release.
  -      mkdir -p $out/include/config
  +    ''
  +    # Some builds (e.g. KVM) want a kernel.release.
  +    + '' mkdir -p $out/include/config
         echo "${version}-default" > $out/include/config/kernel.release
  +    ''
  +    # These oddly named file records teh `SHELL` passed, which causes bootstrap
  +    # tools run-time dependency.
  +    + ''
  +      find "$out" -name '..install.cmd' -print0 | xargs -0 rm
       '';
   
       meta = with lib; {
  
positive.code:   linuxHeaders = common {
      version = "4.18.3";
      sha256 = "1m23hjd02bg8mqnd8dc4z4m3kxds1cyrc6j5saiwnhzbz373rvc1";
      # TODO make unconditional next mass rebuild
      patches = [
         ./no-relocs.patch # for building x86 kernel headers on non-ELF platforms
         ./no-dynamic-cc-version-check.patch # so we can use `stdenvNoCC`, see `makeFlags` above
  
negative.code:     # It may look odd that we use `stdenvNoCC`, and yet explicit depend on a cc.
      # We do this so we have a build->build, not build->host, C compiler.
      depsBuildBuild = [ buildPackages.stdenv.cc ];
      # `elf-header` is null when libc provides `elf.h`.
      nativeBuildInputs = [ perl elf-header ];
  
      extraIncludeDirs = lib.optional stdenvNoCC.hostPlatform.isPowerPC ["ppc"];
  
  