anchor.diff:    openssl-sys = attrs: {
       buildInputs = [ pkgconfig openssl ];
     };
  +
     dbus = attrs: {
       buildInputs = [ pkgconfig dbus_libs ];
     };
  
positive.code: { stdenv, pkgconfig, curl, darwin, libiconv, libgit2, libssh2,
    openssl, sqlite, zlib, dbus_libs, dbus_glib, gdk_pixbuf, cairo, python3, ... }:
  
  let
    inherit (darwin.apple_sdk.frameworks) CoreFoundation;
  
negative.code:   xcb = attrs: {
      buildInputs = [ python3 ];
    };
  
    thrussh-libsodium = attrs: {
      buildInputs = [ pkgconfig libsodium ];
    };
  }
  