anchor.diff:  { stdenv, lib, fetchurl, openssl, libtool, perl, libxml2
  -, enableSeccomp ? false, libseccomp ? null }:
  +, enableSeccomp ? false, libseccomp ? null, buildPackages
  +}:
   
   assert enableSeccomp -> libseccomp != null;
   
  
positive.code:     stdenv.lib.optional enableSeccomp libseccomp;
  
    STD_CDEFINES = [ "-DDIG_SIGCHASE=1" ]; # support +sigchase
  
    configureFlags = [
      "--localstatedir=/var"
  
negative.code:     "--without-pkcs11"
      "--without-purify"
      "--without-python"
      "--with-randomdev=/dev/random"
      "--with-ecdsa"
      "--with-gost"
      "--without-eddsa"
      "--with-aes"
    ] ++ lib.optional enableSeccomp "--enable-seccomp";
  
    postInstall = ''
  