anchor.diff:                mkdir -p $out/lib
                 cp -pd ${boost}/lib/{libboost_context*,libboost_thread*,libboost_system*} $out/lib
                 rm -f $out/lib/*.a
  -              ${lib.optionalString stdenv.isLinux ''
  +              ${lib.optionalString currentStdenv.isLinux ''
                   chmod u+w $out/lib/*.so.*
  -                patchelf --set-rpath $out/lib:${stdenv.cc.cc.lib}/lib $out/lib/libboost_thread.so.*
  +                patchelf --set-rpath $out/lib:${currentStdenv.cc.cc.lib}/lib $out/lib/libboost_thread.so.*
                 ''}
               '';
   
  
positive.code: 
        crossSystems = [ "armv6l-linux" "armv7l-linux" ];
  
        forAllSystems = f: nixpkgs.lib.genAttrs systems (system: f system);
  
        # Memoize nixpkgs for different platforms for efficiency.
        nixpkgsFor = forAllSystems (system:
          import nixpkgs {
            inherit system;
            overlays = [ self.overlay ];
          }
        );
  
        commonDeps = pkgs: with pkgs; rec {
          # Use "busybox-sandbox-shell" if present,
  
negative.code:                 pkgs.perl
                  boost
                ]
                ++ lib.optional (currentStdenv.isLinux || currentStdenv.isDarwin) libsodium
                ++ lib.optional currentStdenv.isDarwin darwin.apple_sdk.frameworks.Security;
  
              configureFlags = ''
                --with-dbi=${perlPackages.DBI}/${pkgs.perl.libPrefix}
  