anchor.diff:              patchelf --set-rpath $out/lib:${stdenv.cc.cc.lib}/lib $out/lib/libboost_thread.so.*
             ''}
           '' +
  -        # For Nix-2.3, patch around an issue where the Nix configure step pulls in the
  +        # For Nix 3.0, patch around an issue where the Nix configure step pulls in the
           # build system's bash and other utilities when cross-compiling
  -        lib.optionalString (stdenv.buildPlatform != stdenv.hostPlatform && isExactly23) ''
  +        lib.optionalString (stdenv.buildPlatform != stdenv.hostPlatform && isExactly30) ''
             mkdir tmp/
             substitute corepkgs/config.nix.in tmp/config.nix.in \
               --subst-var-by bash ${bash}/bin/bash \
  
positive.code: 
    nixUnstable = lib.lowPrio (callPackage common rec {
      name = "nix-3.0${suffix}";
      suffix = "pre20200829_f156513";
  
      src = fetchFromGitHub {
        owner = "NixOS";
        repo = "nix";
        rev = "f15651303f8596bf34c67fc8d536b1e9e7843a87";
        hash = "sha256-HqM3Z4DLdMrf+0PPZL9ysctGg+K+i3S/IHA1GsJj0Ro=";
      };
  
      inherit storeDir stateDir confDir boehmgc;
  
negative.code:   { lib, stdenv, fetchpatch, perl, curl, bzip2, sqlite, openssl ? null, xz
    , bash, coreutils, gzip, gnutar
    , pkgconfig, boehmgc, perlPackages, libsodium, brotli, boost, editline, nlohmann_json
    , autoreconfHook, autoconf-archive, bison, flex
    , jq, libarchive
    , lowdown, mdbook
    # Used by tests
    , gmock
    , busybox-sandbox-shell
  