(gdb) bt full
#0  0x00007f56b22ed387 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:55
        resultvar = 0
        pid = 43964
        selftid = 44026
#1  0x00007f56b22eea78 in __GI_abort () at abort.c:90
        save_stage = 2
        act = {__sigaction_handler = {sa_handler = 0x7f56b267f1c0 <_IO_2_1_stderr_>, sa_sigaction = 0x7f56b267f1c0 <_IO_2_1_stderr_>}, sa_mask = {__val = {140010334088137, 0, 140010333606643, 140006268605560, 140010337071552, 1, 140010337071683, 
              140010337055616, 140010333612814, 140010337071552, 10, 140007411030768, 140006253596200, 140007679379969, 140010333614083, 140010337071552}}, sa_flags = -1295766512, sa_restorer = 0x109ffd0 <stderr>}
        sigs = {__val = {32, 0 <repeats 15 times>}}
#2  0x00007f56b2c3863c in __gnu_cxx::__verbose_terminate_handler () at /tmp/deploy/objdir/../gcc-10.2.0/libstdc++-v3/libsupc++/vterminate.cc:95
        terminating = false
        t = <optimized out>
#3  0x0000000000b53a8b in backtrace_terminate_handler() () at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/utilities/terminate_handler.cc:88
No locals.
#4  0x00007f56b2c438f6 in __cxxabiv1::__terminate(void (*)()) () at /tmp/deploy/objdir/../gcc-10.2.0/libstdc++-v3/libsupc++/eh_terminate.cc:48
No locals.
#5  0x00007f56b2c43961 in std::terminate () at /tmp/deploy/objdir/../gcc-10.2.0/libstdc++-v3/libsupc++/eh_terminate.cc:58
No locals.
#6  0x00007f56b2c43bf4 in __cxxabiv1::__cxa_throw (obj=obj@entry=0x7f5604000980, tinfo=tinfo@entry=0x109a3a8 <typeinfo for boost::exception_detail::error_info_injector<std::logic_error>>, 
    dest=dest@entry=0xbb69f0 <boost::exception_detail::error_info_injector<std::logic_error>::~error_info_injector()>) at /tmp/deploy/objdir/../gcc-10.2.0/libstdc++-v3/libsupc++/eh_throw.cc:95
        globals = <optimized out>
        header = 0x7f5604000900
#7  0x0000000000542ccd in cb::throwWithTrace<std::logic_error> (exception=...) at /home/couchbase/jenkins/workspace/couchbase-server-unix/server_build/tlm/deps/boost.exploded/include/boost/exception/info.hpp:129
No locals.
#8  0x00000000008db6ac in ThrowExceptionPolicy<unsigned long>::nonMonotonic(unsigned long const&, unsigned long const&) [clone .isra.0] () at /opt/gcc-10.2.0/include/c++/10.2.0/bits/char_traits.h:322
No locals.
#9  0x00000000008ddf5d in store (memoryOrder=std::memory_order_seq_cst, desired=<optimized out>, this=0x7f55bf847ec0) at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/dcp/active_stream.cc:1525
        current = <optimized out>
#10 ActiveStream::snapshot(ActiveStream::OutstandingItemsResult const&, std::deque<std::unique_ptr<DcpResponse, std::default_delete<DcpResponse> >, std::allocator<std::unique_ptr<DcpResponse, std::default_delete<DcpResponse> > > >&, unsigned long, std::optional<unsigned long>) () at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/dcp/active_stream.cc:1484
No locals.
#11 0x00000000008e6be1 in ActiveStream::processItems(ActiveStream::OutstandingItemsResult&, std::lock_guard<std::mutex> const&) () at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/dcp/active_stream.cc:1336
        qi = @0x7f55bebc4318: <error reading variable>
        __for_range = @0x7f5613fed1d8: {<std::_Vector_base<SingleThreadedRCPtr<Item, Item*, std::default_delete<Item> >, std::allocator<SingleThreadedRCPtr<Item, Item*, std::default_delete<Item> > > >> = {
            _M_impl = {<std::allocator<SingleThreadedRCPtr<Item, Item*, std::default_delete<Item> > >> = {<__gnu_cxx::new_allocator<SingleThreadedRCPtr<Item, Item*, std::default_delete<Item> > >> = {<No data fields>}, <No data fields>}, <std::_Vector_base<SingleThreadedRCPtr<Item, Item*, std::default_delete<Item> >, std::allocator<SingleThreadedRCPtr<Item, Item*, std::default_delete<Item> > > >::_Vector_impl_data> = {_M_start = 0x7f55bebc4300, _M_finish = 0x7f55bebc43c8, 
                _M_end_of_storage = 0x7f55bebc4400}, <No data fields>}}, <No data fields>}
        mutations = {<std::_Deque_base<std::unique_ptr<DcpResponse, std::default_delete<DcpResponse> >, std::allocator<std::unique_ptr<DcpResponse, std::default_delete<DcpResponse> > > >> = {
            _M_impl = {<std::allocator<std::unique_ptr<DcpResponse, std::default_delete<DcpResponse> > >> = {<__gnu_cxx::new_allocator<std::unique_ptr<DcpResponse, std::default_delete<DcpResponse> > >> = {<No data fields>}, <No data fields>}, <std::_Deque_base<std::unique_ptr<DcpResponse, std::default_delete<DcpResponse> >, std::allocator<std::unique_ptr<DcpResponse, std::default_delete<DcpResponse> > > >::_Deque_impl_data> = {_M_map = 0x7f55bfaf3100, _M_map_size = 8, _M_start = {
                  _M_cur = 0x7f55bf7f0600, _M_first = 0x7f55bf7f0600, _M_last = 0x7f55bf7f0800, _M_node = 0x7f55bfaf3118}, _M_finish = {_M_cur = 0x7f55bf7f0608, _M_first = 0x7f55bf7f0600, _M_last = 0x7f55bf7f0800, 
                  _M_node = 0x7f55bfaf3118}}, <No data fields>}}, <No data fields>}
        visibleSeqno = 392216
        highNonVisibleSeqno = {<std::_Optional_base<unsigned long, true, true>> = {<std::_Optional_base_impl<unsigned long, std::_Optional_base<unsigned long, true, true> >> = {<No data fields>}, 
            _M_payload = {<std::_Optional_payload_base<unsigned long>> = {_M_payload = {_M_empty = {<No data fields>}, _M_value = 0}, 
                _M_engaged = false}, <No data fields>}}, <std::_Enable_copy_move<true, true, true, true, std::optional<unsigned long> >> = {<No data fields>}, <No data fields>}
#12 0x00000000008e743c in ActiveStream::nextCheckpointItemTask(std::lock_guard<std::mutex> const&) () at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/dcp/active_stream.cc:1009
        res = {checkpointType = Memory, historical = Yes, items = {<std::_Vector_base<SingleThreadedRCPtr<Item, Item*, std::default_delete<Item> >, std::allocator<SingleThreadedRCPtr<Item, Item*, std::default_delete<Item> > > >> = {
              _M_impl = {<std::allocator<SingleThreadedRCPtr<Item, Item*, std::default_delete<Item> > >> = {<__gnu_cxx::new_allocator<SingleThreadedRCPtr<Item, Item*, std::default_delete<Item> > >> = {<No data fields>}, <No data fields>}, <std::_Vector_base<SingleThreadedRCPtr<Item, Item*, std::default_delete<Item> >, std::allocator<SingleThreadedRCPtr<Item, Item*, std::default_delete<Item> > > >::_Vector_impl_data> = {_M_start = 0x7f55bebc4300, _M_finish = 0x7f55bebc43c8, 
                  _M_end_of_storage = 0x7f55bebc4400}, <No data fields>}}, <No data fields>}, 
          diskCheckpointState = {<std::_Optional_base<ActiveStream::OutstandingItemsResult::DiskCheckpointState, true, true>> = {<std::_Optional_base_impl<ActiveStream::OutstandingItemsResult::DiskCheckpointState, std::_Optional_base<ActiveStream::OutstandingItemsResult::DiskCheckpointState, true, true> >> = {<No data fields>}, _M_payload = {<std::_Optional_payload_base<ActiveStream::OutstandingItemsResult::DiskCheckpointState>> = {_M_payload = {_M_empty = {<No data fields>}, _M_value = {
                      highCompletedSeqno = 1}}, 
                  _M_engaged = false}, <No data fields>}}, <std::_Enable_copy_move<true, true, true, true, std::optional<ActiveStream::OutstandingItemsResult::DiskCheckpointState> >> = {<No data fields>}, <No data fields>}, visibleSeqno = 392216, 
          ranges = {<std::_Vector_base<CheckpointSnapshotRange, std::allocator<CheckpointSnapshotRange> >> = {
              _M_impl = {<std::allocator<CheckpointSnapshotRange>> = {<__gnu_cxx::new_allocator<CheckpointSnapshotRange>> = {<No data fields>}, <No data fields>}, <std::_Vector_base<CheckpointSnapshotRange, std::allocator<CheckpointSnapshotRange> >::_Vector_impl_data> = {_M_start = 0x7f55be7ced40, _M_finish = 0x7f55be7ceec0, _M_end_of_storage = 0x7f55be7ceef0}, <No data fields>}}, <No data fields>}}
        producer = {<std::__shared_ptr<DcpProducer, (__gnu_cxx::_Lock_policy)2>> = {<std::__shared_ptr_access<DcpProducer, (__gnu_cxx::_Lock_policy)2, false, false>> = {<No data fields>}, _M_ptr = <optimized out>, _M_refcount = {
              _M_pi = 0x7f55bf5a4900}}, <No data fields>}

        vbucket = {<std::__shared_ptr<VBucket, (__gnu_cxx::_Lock_policy)2>> = {<std::__shared_ptr_access<VBucket, (__gnu_cxx::_Lock_policy)2, false, false>> = {<No data fields>}, _M_ptr = 0x7f55bfb88200, _M_refcount = {
              _M_pi = 0x7f55bf4ac5c0}}, <No data fields>}
---Type <return> to continue, or q <return> to quit---
#13 0x00000000008e7564 in ActiveStream::nextCheckpointItemTask() () at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/dcp/active_stream.cc:993
        lh = {_M_device = @0x7f55bf847df8}
#14 0x00000000008ee299 in ActiveStreamCheckpointProcessorTask::run() () at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/dcp/active_stream_checkpoint_processor_task.cc:52
        as = <optimized out>
        rh = {<StreamContainer<std::shared_ptr<ActiveStream> >::Iterable<std::_Fwd_list_const_iterator<std::shared_ptr<ActiveStream> > >> = {itr = {_M_node = 0x7f55be32b020}, endItr = {_M_node = 0x0}, before = {_M_node = <optimized out>}}, readLock = {
            _M_pm = 0x7f55bfd041d8, _M_owns = <optimized out>}, container = <optimized out>}
        streams = {<std::__shared_ptr<StreamContainer<std::shared_ptr<ActiveStream> >, (__gnu_cxx::_Lock_policy)2>> = {<std::__shared_ptr_access<StreamContainer<std::shared_ptr<ActiveStream> >, (__gnu_cxx::_Lock_policy)2, false, false>> = {<No data fields>}, _M_ptr = 0x7f55bfd041c0, _M_refcount = {_M_pi = 0x7f55bfd041b0}}, <No data fields>}
        iterations = 0
        expected = false
#15 0x0000000000ac2099 in GlobalTask::execute(std::basic_string_view<char, std::char_traits<char> >) () at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/executor/globaltask.cc:98
        guard = {previous = 0x0}
        start = <optimized out>
        runAgain = <optimized out>
#16 0x0000000000abb77a in FollyExecutorPool::TaskProxy::scheduleViaCPUPool()::{lambda()#2}::operator()() const (__closure=0x7f5613fed650) at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/executor/folly_executorpool.cc:309
        runAgain = <optimized out>
        proxy = @0x7f5670f699f0: <error reading variable>
#17 0x0000000000ac344e in operator() (this=0x7f5613fed650) at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/executor/cancellable_cpu_executor.cc:42
        fn = @0x7f5613fed650: {<folly::detail::function::FunctionTraits<void()>> = {<No data fields>}, data_ = {big = 0x7f5670f699f0, tiny = {
              __data = "\360\231\366pV\177\000\000@\327\376\023V\177\000\000\000\000\000\000\000\000\000\000\240L\331\260V\177\000\000\177\003\000\000\000\000\000\000\335\037\301\000\000\000\000", __align = {<No data fields>}}}, 
          call_ = 0xabbc90 <folly::detail::function::FunctionTraits<void ()>::callSmall<FollyExecutorPool::TaskProxy::scheduleViaCPUPool()::{lambda()#2}>(folly::detail::function::Data&)>, 
          exec_ = 0xaba1a0 <folly::detail::function::execSmall<FollyExecutorPool::TaskProxy::scheduleViaCPUPool()::{lambda()#2}>(folly::detail::function::Op, folly::detail::function::Data*, folly::detail::function::Data)>}
#18 CancellableCPUExecutor::add(GlobalTask*, folly::Function<void ()>)::{lambda()#1}::operator()() const () at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/executor/cancellable_cpu_executor.cc:42
        task = {storage_ = {{emptyState = -128 '\200', value = {task = 0x7f559adc8480, func = {<folly::detail::function::FunctionTraits<void()>> = {<No data fields>}, data_ = {big = 0x7f5670f699f0, tiny = {
                      __data = "\360\231\366pV\177\000\000@\327\376\023V\177\000\000\000\000\000\000\000\000\000\000\240L\331\260V\177\000\000\177\003\000\000\000\000\000\000\335\037\301\000\000\000\000", __align = {<No data fields>}}}, 
                  call_ = 0xabbc90 <folly::detail::function::FunctionTraits<void ()>::callSmall<FollyExecutorPool::TaskProxy::scheduleViaCPUPool()::{lambda()#2}>(folly::detail::function::Data&)>, 
                  exec_ = 0xaba1a0 <folly::detail::function::execSmall<FollyExecutorPool::TaskProxy::scheduleViaCPUPool()::{lambda()#2}>(folly::detail::function::Op, folly::detail::function::Data*, folly::detail::function::Data)>}}}, hasValue = true}}
        this = <optimized out>
#19 0x0000000000c215b0 in operator() (this=0x7f5613fed840) at /home/couchbase/jenkins/cbdeps-ws/deps/packages/build/folly/folly-prefix/src/folly/folly/Function.h:416
        fn = @0x7f5613fed840: {<folly::detail::function::FunctionTraits<void()>> = {<No data fields>}, data_ = {big = 0x7f56b0d46c00, tiny = {
              __data = "\000l\324\260V\177\000\000\320\247\n\265V\177\000\000\060\000\000\000\000\000\000\000\372\253\000\000\000\000\000\000`\000\000\000\000\000\000\000\020\331\376\023V\177\000", __align = {<No data fields>}}}, 
          call_ = 0xac37d0 <folly::detail::function::FunctionTraits<void()>::callSmall<CancellableCPUExecutor::add(GlobalTask*, folly::Func)::<lambda()> >(folly::detail::function::Data &)>, 
          exec_ = 0xac2d80 <folly::detail::function::execSmall<CancellableCPUExecutor::add(GlobalTask*, folly::Func)::<lambda()> >(folly::detail::function::Op, folly::detail::function::Data *, folly::detail::function::Data *)>}
#20 folly::ThreadPoolExecutor::runTask(std::shared_ptr<folly::ThreadPoolExecutor::Thread> const&, folly::ThreadPoolExecutor::Task&&) (this=this@entry=0x7f56b0d46d00, thread=..., 
    task=task@entry=<unknown type in /usr/lib/debug/opt/couchbase/bin/memcached-7.2.1-5919.x86_64.debug, CU 0xaa3a58a, DIE 0xaabe4bf>)
    at /home/couchbase/jenkins/cbdeps-ws/deps/packages/build/folly/folly-prefix/src/folly/folly/executors/ThreadPoolExecutor.cpp:97
        rctx = {prev_ = {<std::__shared_ptr<folly::RequestContext, (__gnu_cxx::_Lock_policy)2>> = {<std::__shared_ptr_access<folly::RequestContext, (__gnu_cxx::_Lock_policy)2, false, false>> = {<No data fields>}, _M_ptr = 0x0, _M_refcount = {
                _M_pi = 0x0}}, <No data fields>}}
        startTime = {__d = {__r = 54154389859107225}}
        stats = {expired = false, waitTime = {__r = 45608}, runTime = {__r = 0}, enqueueTime = {__d = {__r = 54154389859061617}}, requestId = 0}
#21 0x0000000000c0c04a in folly::CPUThreadPoolExecutor::threadRun (this=0x7f56b0d46d00, thread=...) at /home/couchbase/jenkins/cbdeps-ws/deps/packages/build/folly/folly-prefix/src/folly/folly/executors/CPUThreadPoolExecutor.cpp:265
        task = {storage_ = {{emptyState = 0 '\000', value = {<folly::ThreadPoolExecutor::Task> = {func_ = {<folly::detail::function::FunctionTraits<void()>> = {<No data fields>}, data_ = {big = 0x7f56b0d46c00, tiny = {
                        __data = "\000l\324\260V\177\000\000\320\247\n\265V\177\000\000\060\000\000\000\000\000\000\000\372\253\000\000\000\000\000\000`\000\000\000\000\000\000\000\020\331\376\023V\177\000", __align = {<No data fields>}}}, 
                    call_ = 0xac37d0 <folly::detail::function::FunctionTraits<void()>::callSmall<CancellableCPUExecutor::add(GlobalTask*, folly::Func)::<lambda()> >(folly::detail::function::Data &)>, 
                    exec_ = 0xac2d80 <folly::detail::function::execSmall<CancellableCPUExecutor::add(GlobalTask*, folly::Func)::<lambda()> >(folly::detail::function::Op, folly::detail::function::Data *, folly::detail::function::Data *)>}, 
                  enqueueTime_ = {__d = {__r = 54154389859061617}}, expiration_ = {__r = 0}, expireCallback_ = {<folly::detail::function::FunctionTraits<void()>> = {<No data fields>}, data_ = {big = 0xabfa, tiny = {
                        __data = "\372\253\000\000\000\000\000\000\033#\247", '\000' <repeats 13 times>, "_\356\351\264V\177\000\000\240\331\376\023V\177\000\000@\206\n\265V\177\000", __align = {<No data fields>}}}, call_ = 0x466e81
     <folly::detail::function::FunctionTraits<void ()>::uninitCall(folly::detail::function::Data&)>, exec_ = 0x0}, 
                  context_ = {<std::__shared_ptr<folly::RequestContext, (__gnu_cxx::_Lock_policy)2>> = {<std::__shared_ptr_access<folly::RequestContext, (__gnu_cxx::_Lock_policy)2, false, false>> = {<No data fields>}, _M_ptr = 0x0, _M_refcount = {
                        _M_pi = 0x0}}, <No data fields>}}, poison = false, priority_ = 0 '\000', queueObserverPayload_ = 140010309838096}}, hasValue = true}}
        guard = {list_ = {forbid = true, prev = 0x0, curr = {name = {static npos = <optimized out>, b_ = 0xce8673 "CPUThreadPoolExecutor", e_ = 0xce8688 ""}}}}
#22 0x0000000000c24569 in __invoke_impl<void, void (folly::ThreadPoolExecutor::*&)(std::shared_ptr<folly::ThreadPoolExecutor::Thread>), folly::ThreadPoolExecutor*&, std::shared_ptr<folly::ThreadPoolExecutor::Thread>&> (__t=<optimized out>, 
    __f=<optimized out>) at /usr/local/include/c++/7.3.0/bits/invoke.h:73
No locals.
#23 __invoke<void (folly::ThreadPoolExecutor::*&)(std::shared_ptr<folly::ThreadPoolExecutor::Thread>), folly::ThreadPoolExecutor*&, std::shared_ptr<folly::ThreadPoolExecutor::Thread>&> (__fn=<optimized out>)
    at /usr/local/include/c++/7.3.0/bits/invoke.h:95
No locals.
#24 __call<void, 0, 1> (__args=<optimized out>, this=<optimized out>) at /usr/local/include/c++/7.3.0/functional:467
No locals.
#25 operator()<> (this=<optimized out>) at /usr/local/include/c++/7.3.0/functional:551
No locals.
#26 folly::detail::function::FunctionTraits<void ()>::callBig<std::_Bind<void (folly::ThreadPoolExecutor::*(folly::ThreadPoolExecutor*, std::shared_ptr<folly::ThreadPoolExecutor::Thread>))(std::shared_ptr<folly::ThreadPoolExecutor::Thread>)> >(folly::det---Type <return> to continue, or q <return> to quit---
ail::function::Data&) (p=...) at /home/couchbase/jenkins/cbdeps-ws/deps/packages/build/folly/folly-prefix/src/folly/folly/Function.h:401
        fn = <optimized out>
#27 0x0000000000abb474 in operator() (this=0x7f56b11f2240) at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/executor/folly_executorpool.cc:49
        fn = @0x7f56b11f2240: <error reading variable>
#28 operator() (__closure=0x7f56b11f2240) at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/executor/folly_executorpool.cc:49
        threadNameOpt = {storage_ = {{emptyState = -96 '\240', value = {static npos = 18446744073709551615, _M_dataplus = {<std::allocator<char>> = {<__gnu_cxx::new_allocator<char>> = {<No data fields>}, <No data fields>}, 
                  _M_p = 0x7f5613fed9a0 "NonIoPool3"}, _M_string_length = 10, {_M_local_buf = "NonIoPool3\000\000\000\000\000", _M_allocated_capacity = 8029725099528449870}}}, hasValue = true}}
        func = <error reading variable func (Cannot access memory at address 0x7f56b11f2240)>
#29 folly::detail::function::FunctionTraits<void ()>::callBig<CBRegisteredThreadFactory::newThread(folly::Function<void ()>&&)::{lambda()#1}>(folly::detail::function::Data&) (p=...)
    at /home/couchbase/jenkins/workspace/couchbase-server-unix/server_build/tlm/deps/folly.exploded/include/folly/Function.h:401
        fn = @0x7f56b11f2240: <error reading variable>
#30 0x00007f56b2c6cd40 in execute_native_thread_routine () at /tmp/deploy/objdir/../gcc-10.2.0/libstdc++-v3/src/c++11/thread.cc:80
No locals.
#31 0x00007f56b4a6dea5 in start_thread (arg=0x7f5613fff700) at pthread_create.c:307
        __res = <optimized out>
        pd = 0x7f5613fff700
        now = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140007679457024, 3056305910517021729, 0, 8392704, 0, 140007679457024, -3114791140431545311, -3114442251773592543}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, 
              cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
        pagesize_m1 = <optimized out>
        sp = <optimized out>
        freesize = <optimized out>
#32 0x00007f56b23b5b0d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111
No locals.
(gdb)