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.
// Boost Filesystem cerrno.hpp header --------------------------------------//
// Copyright Beman Dawes 2005.
// Use, modification, and distribution is subject to 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)
// See library home page at http://www.boost.org/libs/filesystem
#ifndef BOOST_FILESYSTEM_CERRNO_HPP
#define BOOST_FILESYSTEM_CERRNO_HPP
#include <cerrno>
#if defined __BORLANDC__
#define ENOSYS 9997
#endif
#define EBADHANDLE 9998 // bad handle
#define EOTHER 9999 // Other error not translatable
// to a POSIX errno value
#endif // include guard