anchor.diff:  { fetchurl, fetchpatch, stdenv, lib, pkgconfig
  -, libgpgerror, libassuan, libcap ? null, ncurses ? null, gtk2 ? null, gcr ? null, qt4 ? null
  +, libgpgerror, libassuan, libcap ? null, libsecret ? null, ncurses ? null, gtk2 ? null, gcr ? null, qt4 ? null
   }:
   
   let
  
positive.code:     sha256 = "0ni7g4plq6x78p32al7m8h2zsakvg1rhfz0qbc3kdc7yq7nw4whn";
    };
  
    buildInputs = [ libgpgerror libassuan libcap gtk2 gcr ncurses qt4 ];
  
    prePatch = ''
      substituteInPlace pinentry/pinentry-curses.c --replace ncursesw ncurses
  
negative.code:   '';
  
    configureFlags = [
      (mkWith   (libcap != null)    "libcap")
      (mkEnable (libsecret != null) "libsecret")
      (mkEnable (ncurses != null)   "pinentry-curses")
      (mkEnable true                "pinentry-tty")
      (mkEnable (gtk2 != null)      "pinentry-gtk2")
      (mkEnable (gcr != null)       "pinentry-gnome3")
      (mkEnable (qt4 != null)       "pinentry-qt")
    ];
  
    nativeBuildInputs = [ pkgconfig ];
  