We create our customised manager which will fork child process with baseManager. Because we registered SIGCHLD to reap the zombie for manager, we found this causes baseManager raise RemoteError when called twice.(Test script attached.)

After look at baseManager.py we found recv() in handling the request has been interrupted by comming SIGCHLD, not retry recv(), but raise to client side directly.
try:

                methodname = obj = None

                request = recv()<------------------this line been interrupted by SIGCHLD

                ident, methodname, args, kwds = request

                obj, exposed, gettypeid = id_to_obj[ident]

                if methodname not in exposed:

                    raise AttributeError(

                        'method %r of %r object is not in exposed=%r' %

                        (methodname, type(obj), exposed)

                        )

                function = getattr(obj, methodname)
                try:

                    res = function(*args, **kwds)

                except Exception, e:

                    msg = ('#ERROR', e)

                else:

                    typeid = gettypeid and gettypeid.get(methodname, None)

                    if typeid:

                        rident, rexposed = self.create(conn, typeid, res)

                        token = Token(typeid, self.address, rident)

                        msg = ('#PROXY', (rexposed, token))

                    else:

                        msg = ('#RETURN', res)
            except AttributeError:
                if methodname is None:
                    msg = ('#TRACEBACK', format_exc())
                else:
                    try:
                        fallback_func = self.fallback_mapping[methodname]
                        result = fallback_func(
                            self, conn, ident, obj, *args, **kwds
                            )
                        msg = ('#RETURN', result)
                    except Exception:
                        msg = ('#TRACEBACK', format_exc())

            except EOFError:
                util.debug('got EOF -- exiting thread serving %r',
                           threading.current_thread().name)
                sys.exit(0)

            except Exception:<------does not handle IOError,INTR here should retry recv() 
                msg = ('#TRACEBACK', format_exc())

New changeset bc34fe4a0d58 by Richard Oudkerk in branch '2.7':
Issue #17097: Make multiprocessing ignore EINTR.
http://hg.python.org/cpython/rev/bc34fe4a0d58

New changeset 3ec5267f51ff by Richard Oudkerk in branch '3.3':
Issue #17097: Make multiprocessing ignore EINTR.
http://hg.python.org/cpython/rev/3ec5267f51ff

New changeset 035577781505 by Richard Oudkerk in branch 'default':
Issue #17097: Merge.
http://hg.python.org/cpython/rev/035577781505