Commented out export of missing CRML source file to avoid build error.
There are no known side effects of this file being missing, so this seems a reasonable way to avoid the build error.
///////////////////////////////////////////////////////////////////////////////
/// \file xpressive.hpp
/// Includes all of xpressive including support for both static and
/// dynamic regular expressions.
//
// Copyright 2004 Eric Niebler. Distributed under the Boost
// Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
#ifndef BOOST_XPRESSIVE_HPP_EAN_10_04_2005
#define BOOST_XPRESSIVE_HPP_EAN_10_04_2005
// MS compatible compilers support #pragma once
#if defined(_MSC_VER) && (_MSC_VER >= 1020)
# pragma once
#endif
#include <boost/xpressive/xpressive_static.hpp>
#include <boost/xpressive/xpressive_dynamic.hpp>
#endif