Ceph

https://jenkins.ceph.com/job/ceph-pull-requests/73037/consoleFull#-2125701813e4bfde06-44c1-4b3c-8379-d9ee175fb257

/home/jenkins-build/build/workspace/ceph-pull-requests/src/common/async/completion.h:194:29: error: 'boost::asio::executor_work_guard<boost::asio::execution::any_executor<boost::asio::execution::context_as_t<boost::asio::execution_context&>, boost::asio::execution::detail::blocking::never_t<0>, boost::asio::execution::prefer_only<boost::asio::execution::detail::blocking::possibly_t<0> >, boost::asio::execution::prefer_only<boost::asio::execution::detail::outstanding_work::tracked_t<0> >, boost::asio::execution::prefer_only<boost::asio::execution::detail::outstanding_work::untracked_t<0> >, boost::asio::execution::prefer_only<boost::asio::execution::detail::relationship::fork_t<0> >, boost::asio::execution::prefer_only<boost::asio::execution::detail::relationship::continuation_t<0> > >, void>::executor_type' {aka 'class boost::asio::execution::any_executor<boost::asio::execution::context_as_t<boost::asio::execution_context&>, boost::asio::execution::detail::blocking::never_t<0>, boost::asio::execution::prefer_only<boost::asio::execution::detail::blocking::possibly_t<0> >, boost::asio::execution::prefer_only<boost::asio::execution::detail::outstanding_work::tracked_t<0> >, boost::asio::execution::prefer_only<boost::asio::execution::detail::outstanding_work::untracked_t<0> >, boost::asio::execution::prefer_only<boost::asio::execution::detail::relationship::fork_t<0> >, boost::asio::execution::prefer_only<boost::asio::execution::detail::relationship::continuation_t<0> > >'} has no member named 'defer'; did you mean 'prefer'?
194 | w.second.get_executor().defer(std::move(f), alloc2);

See also https://github.com/ceph/ceph/pull/40677#issuecomment-815955892