anchor.diff:  { stdenv
   , fetchurl
   , fetchpatch
  +, libmysqlclient
   # Excerpt from glpk's INSTALL file:
   # This feature allows the exact simplex solver to use the GNU MP
   # bignum library. If it is disabled, the exact simplex solver uses the
  
positive.code:     })
    ];
  
    doCheck = true;
  
    meta = {
  
negative.code:     sha256 = "040sfaa9jclg2nqdh83w71sv9rc1sznpnfiripjdyr48cady50a2";
    };
  
    buildInputs =
      [ libmysqlclient
      ] ++ stdenv.lib.optionals withGmp [
        gmp
      ];
  
    configureFlags = stdenv.lib.optionals withGmp [
      "--with-gmp"
  