anchor.diff:  { stdenv, pkg-config, curl, darwin, libiconv, libgit2, libssh2,
     openssl, sqlite, zlib, dbus, dbus-glib, gdk-pixbuf, cairo, python3,
  -  libsodium, postgresql, gmp, foundationdb, ... }:
  +  libsodium, postgresql, gmp, foundationdb, capnproto, nettle, clang,
  +  llvmPackages, ... }:
   
   let
     inherit (darwin.apple_sdk.frameworks) CoreFoundation Security;
  
positive.code:     propagatedBuildInputs = [ Security ];
    };
  
    serde_derive = attrs: {
      buildInputs = stdenv.lib.optional stdenv.isDarwin Security;
    };
  
negative.code:     buildInputs = [ dbus ];
    };
  
    nettle-sys = attrs: {
      nativeBuildInputs = [ pkg-config ];
      buildInputs = [ nettle clang ];
      LIBCLANG_PATH = "${llvmPackages.libclang}/lib";
    };
  
    openssl = attrs: {
      buildInputs = [ openssl ];
    };
  