Hi Boosters, I have been trying to build Boost 1.64.0 with Oracle Developer Studio 12.6 on Oracle Solaris 11.3 x86_64. There are two errors encountered during the build. They are: 1. Problem with Boost.Optional with this error messages: "libs/log/src/named_scope.cpp", line 118: Error: Use of overloaded binary operator '=' is ambiguous. "./boost/optional/optional.hpp", line 900: Note: Viable candidate 'boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>& boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>::operator=<boost::log::v2_mt_posix::attributes::named_scope_list&>(boost::log::v2_mt_posix::attributes::named_scope_list&)'. "./boost/optional/optional.hpp", line 962: Note: Viable candidate 'boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>& boost::optional<boost::log::v2_mt_posix::attributes::named_scope_list>::operator=<boost::log::v2_mt_posix::attributes::named_scope_list&>(boost::log::v2_mt_posix::attributes::named_scope_list&)'. 2. Problem with Boost.Python with this error message: "libs/python/src/numpy/dtype.cpp", line 61: Error: NPY_FLOAT16 is not defined. Note that these two errors are the cause of 9 Boost shared libraries to not be generated. I would appreciate it very much if someone could give me some pointers on how to resolve the above issues. Kind regards, Leo