anchor.diff: -{ stdenv, lib, fetchurl, openssl, libtool, perl, libxml2
  +{ stdenv, lib, fetchurl
  +, perl
  +, libcap, libtool, libxml2, openssl
   , enablePython ? false, python3 ? null
   , enableSeccomp ? false, libseccomp ? null, buildPackages
   }:
  
positive.code:     "--without-idn"
      "--without-idnlib"
      "--without-lmdb"
      "--without-pkcs11"
      "--without-purify"
      "--with-randomdev=/dev/random"
  
negative.code:     stdenv.lib.optional stdenv.isDarwin ./darwin-openssl-linking-fix.patch;
  
    nativeBuildInputs = [ perl ];
    buildInputs = [ libcap libtool libxml2 openssl ]
      ++ lib.optional enableSeccomp libseccomp
      ++ lib.optional enablePython python3;
  
  