UBSan failure "object has a possibly invalid vptr" during test "multi_bucket set/get "

 Running [0144/0158]: multi_bucket set/get ...../kv_engine/engines/ep/src/ep_engine.h:669:16: runtime error: member access within address 0x61d001b92280 which does not point to an object of type 'EventuallyPersistentEngine'

 0x61d001b92280: note: object has a possibly invalid vptr: abs(offset to top) too big

  66 2a 00 74  ae 2a 80 24 b9 7f 00 00  a8 97 f6 43 b9 7f 00 00  00 1d b2 01 00 00 00 00  00 00 00 00

               ^~~~~~~~~~~~~~~~~~~~~~~

               possibly invalid vptr

     #0 0x7fb941b10abc in EventuallyPersistentEngine::getConfiguration() build/../kv_engine/engines/ep/src/ep_engine.h:669:16

     #1 0x7fb941f6857d in GlobalTask::~GlobalTask() build/../kv_engine/engines/ep/src/globaltask.cc:66:17

     #2 0x7fb941f5fcd2 in std::_Sp_counted_ptr_inplace<FlusherTask, std::allocator<FlusherTask>, (__gnu_cxx::_Lock_policy)2>::_M_dispose() /usr/include/c++/7.5.0/bits/shared_ptr_base.h:535:2

     #3 0x6e7506 in std::_Sp_counted_base<(__gnu_cxx::_Lock_policy)2>::_M_release() /usr/include/c++/7.5.0/bits/shared_ptr_base.h:154:6

     #4 0x7fb941ab08b6 in std::__shared_ptr<GlobalTask, (__gnu_cxx::_Lock_policy)2>::reset() /usr/include/c++/7.5.0/bits/shared_ptr_base.h:1235:9

     #5 0x7fb941aa2a6a in CB3ExecutorPool::cancel(unsigned long, bool) build/../kv_engine/engines/ep/src/cb3_executorpool.cc:252:14

     #6 0x7fb941aeef09 in CB3ExecutorThread::run() build/../kv_engine/engines/ep/src/cb3_executorthread.cc:196:17

     #7 0x7fb93af5c319 in CouchbaseThread::run() build/../platform/src/cb_pthreads.cc:58:9

     #8 0x7fb93af59e87 in platform_thread_wrap(void*) build/../platform/src/cb_pthreads.cc:71:14

     #9 0x7fb939b9b6da in start_thread (/lib/x86_64-linux-gnu/libpthread.so.0+0x76da)

     #10 0x7fb9394a571e in clone /build/glibc-S7xCS9/glibc-2.27/misc/../sysdeps/unix/sysv/linux/x86_64/clone.S:95

 SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior ../kv_engine/engines/ep/src/ep_engine.h:669:16 in