anchor.diff:    cc != null && binutils != null && coreutils != null && gnugrep != null;
   assert !(nativeLibc && noLibc);
   assert (noLibc || nativeLibc) == (libc == null);
  +
  +assert targetPlatform != hostPlatform -> runCommand != null;
   
   # For ghdl (the vhdl language provider to gcc) we need zlib in the wrapper.
   assert cc.langVhdl or false -> zlib != null;
  
positive.code:   infixSalt  = stdenv.lib.optionalString (targetPlatform != hostPlatform) dashlessTarget;
    infixSalt_ = stdenv.lib.optionalString (targetPlatform != hostPlatform) (dashlessTarget + "_");
    _infixSalt = stdenv.lib.optionalString (targetPlatform != hostPlatform) ("_" + dashlessTarget);
  in
  
  stdenv.mkDerivation {
  
negative.code:     ''
  
      + ''
        substituteAll ${preWrap ./setup-hook.sh} $out/nix-support/setup-hook.tmp
        cat $out/nix-support/setup-hook.tmp >> $out/nix-support/setup-hook
        rm $out/nix-support/setup-hook.tmp
  
  