anchor.diff: -{ stdenv, fetchurl, ncurses, which, perl, gpgme
  +{ stdenv, fetchurl, ncurses, which, perl
   , sslSupport ? true
   , imapSupport ? true
   , headerCache ? true
   , saslSupport ? true
  +, gpgmeSupport ? true
   , gdbm ? null
   , openssl ? null
   , cyrus_sasl ? null
  +, gpgme ? null
   }:
   
   assert headerCache -> gdbm != null;
  
positive.code:   };
  
    buildInputs = [
      ncurses which perl gpgme
      (if headerCache then gdbm else null)
      (if sslSupport then openssl else null)
      (if saslSupport then cyrus_sasl else null)
    ];
    
    configureFlags = [
      "--with-mailpath=" "--enable-smtp"
  
      # This allows calls with "-d N", that output debug info into ~/.muttdebug*
      "--enable-debug" "--enable-pop" "--enable-imap" "--enable-gpgme"
  
      # The next allows building mutt without having anything setgid
      # set by the installer, and removing the need for the group 'mail'
  
negative.code:     (if sslSupport then "--with-ssl" else "--without-ssl")
      (if imapSupport then "--enable-imap" else "--disable-imap")
      (if saslSupport then "--with-sasl" else "--without-sasl")
      (if gpgmeSupport then "--enable-gpgme" else "--disable-gpgme")
    ];
  
    meta = {
  