Ceph

On ceph-15.2.4 & 15.2.5, when I set WITH_BLKIN to ON, I got compilation errors as follow:

/home/dzw/ceph/src/msg/Message.cc: In member function ‘void Message::decode_trace(ceph::buffer::v15_2_0::list::const_iterator&, bool)’:
/home/dzw/ceph/src/msg/Message.cc:972:29: error: invalid use of incomplete type ‘class Messenger’
   const auto endpoint = msgr->get_trace_endpoint();
                             ^~
In file included from /home/dzw/ceph/src/msg/Message.h:34,
                 from /home/dzw/ceph/src/msg/Message.cc:15:
/home/dzw/ceph/src/msg/Connection.h:37:7: note: forward declaration of ‘class Messenger’
 class Messenger;
       ^~~~~~~~~
/home/dzw/ceph/src/msg/Message.cc:976:29: error: invalid use of incomplete type ‘class Messenger’
   } else if (create || (msgr->get_myname().is_osd() &&
                             ^~
In file included from /home/dzw/ceph/src/msg/Message.h:34,
                 from /home/dzw/ceph/src/msg/Message.cc:15:
/home/dzw/ceph/src/msg/Connection.h:37:7: note: forward declaration of ‘class Messenger’
 class Messenger;
       ^~~~~~~~~
/home/dzw/ceph/src/msg/Message.cc:977:29: error: invalid use of incomplete type ‘class Messenger’
                         msgr->cct->_conf->osd_blkin_trace_all)) {
                             ^~
In file included from /home/dzw/ceph/src/msg/Message.h:34,
                 from /home/dzw/ceph/src/msg/Message.cc:15:
/home/dzw/ceph/src/msg/Connection.h:37:7: note: forward declaration of ‘class Messenger’
 class Messenger;
       ^~~~~~~~~
make[2]: *** [src/msg/CMakeFiles/common-msg-objs.dir/build.make:76: src/msg/CMakeFiles/common-msg-objs.dir/Message.cc.o] Error 1
make[1]: *** [CMakeFiles/Makefile2:2157: src/msg/CMakeFiles/common-msg-objs.dir/all] Error 2
make[1]: *** Waiting for unfinished jobs....