Hi, Running the tutorial async TCP server (http://www.boost.org/doc/libs/1_65_1/doc/html/boost_asio/tutorial/tutdaytime...) or any other asynchronous operation in valgrind yields an error like this: = Syscall param epoll_pwait(sigmask) points to unaddressable byte(s) = epoll_pwait (in /usr/lib/libc-2.26.so) = boost::asio::detail::epoll_reactor::run(bool, boost::asio::detail::op_queueboost::asio::detail::task_io_service_operation&) (in /.../server) = boost::asio::detail::task_io_service::do_run_one(boost::asio::detail::scoped_lockboost::asio::detail::posix_mutex&, boost::asio::detail::task_io_service_thread_info&, boost::system::error_code const&) (in /.../server) = boost::asio::detail::task_io_service::run(boost::system::error_code&) (in /.../server) = boost::asio::io_service::run() (in /.../server) = main (in /.../server) = Address 0x0 is not stack'd, malloc'd or (recently) free'd I suspect it's due to some recent changes because it didn't use to be an error. Boost version is 1.65.1(Arch Linux). Thank you.