(gdb) bt full
#0  load (__m=std::memory_order_relaxed, this=0x7fc77835859000) at /usr/local/include/c++/7.3.0/bits/atomic_base.h:396
No locals.
#1  load (this=0x7fc77835859000) at /home/couchbase/jenkins/workspace/couchbase-server-unix/platform/include/platform/non_negative_counter.h:99
No locals.
#2  fetch_sub (arg=34186498402484481, this=0x7fc77835859000) at /home/couchbase/jenkins/workspace/couchbase-server-unix/platform/include/platform/non_negative_counter.h:148
        current = <optimized out>
        desired = 140494695398456
#3  operator-= (rhs=34186498402484481, this=<optimized out>) at /home/couchbase/jenkins/workspace/couchbase-server-unix/platform/include/platform/non_negative_counter.h:190
No locals.
#4  deallocate (n=34186498402484481, p=<optimized out>, this=<optimized out>) at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/utilities/memory_tracking_allocator.h:108
No locals.
#5  deallocate (__n=34186498402484481, __p=<optimized out>, __a=...) at /usr/local/include/c++/7.3.0/bits/alloc_traits.h:328
No locals.
#6  _M_destroy (__size=34186498402484480, this=0x7fc741550d07) at /usr/local/include/c++/7.3.0/bits/basic_string.h:226
No locals.
#7  _M_dispose (this=0x7fc741550d07) at /usr/local/include/c++/7.3.0/bits/basic_string.h:221
No locals.
#8  ~basic_string (this=0x7fc741550d07, __in_chrg=<optimized out>) at /usr/local/include/c++/7.3.0/bits/basic_string.h:647
No locals.
#9  ~StoredDocKeyT (this=<optimized out>, __in_chrg=<optimized out>) at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/storeddockey.h:51
No locals.
#10 ~pair (this=<optimized out>, __in_chrg=<optimized out>) at /usr/local/include/c++/7.3.0/bits/stl_pair.h:198
No locals.
#11 _S_destroy<MemoryTrackingAllocator<std::pair<StoredDocKeyT<MemoryTrackingAllocator> const, index_entry> >, std::pair<StoredDocKeyT<MemoryTrackingAllocator> const, index_entry> > (__p=<optimized out>)
    at /usr/local/include/c++/7.3.0/bits/alloc_traits.h:261
No locals.
#12 destroy<std::pair<StoredDocKeyT<MemoryTrackingAllocator> const, index_entry> > (__a=<synthetic pointer>, __p=<optimized out>) at /usr/local/include/c++/7.3.0/bits/alloc_traits.h:356
No locals.
#13 _M_deallocate_node (__n=0x7fc741550cff, this=0x7fc778697ce0) at /usr/local/include/c++/7.3.0/bits/hashtable_policy.h:2084
No locals.
#14 _M_deallocate_nodes (__n=<optimized out>, this=0x7fc778697ce0) at /usr/local/include/c++/7.3.0/bits/hashtable_policy.h:2097
        __tmp = 0x7fc741550cff
#15 clear (this=0x7fc778697ce0) at /usr/local/include/c++/7.3.0/bits/hashtable.h:2029
No locals.
#16 std::_Hashtable<StoredDocKeyT<MemoryTrackingAllocator>, std::pair<StoredDocKeyT<MemoryTrackingAllocator> const, index_entry>, MemoryTrackingAllocator<std::pair<StoredDocKeyT<MemoryTrackingAllocator> const, index_entry> >, std::__detail::_Select1st, std::equal_to<void>, std::hash<StoredDocKeyT<MemoryTrackingAllocator> >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, false, true> >::~_Hashtable (this=0x7fc778697ce0, __in_chrg=<optimized out>) at /usr/local/include/c++/7.3.0/bits/hashtable.h:1355
No locals.
#17 0x00007fc7bd0a9b1a in ~unordered_map (this=0x7fc778697ce0, __in_chrg=<optimized out>) at /usr/local/include/c++/7.3.0/bits/unordered_map.h:101
No locals.
#18 Checkpoint::~Checkpoint (this=0x7fc778697b80, __in_chrg=<optimized out>) at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/checkpoint.cc:217
No locals.
#19 0x00007fc7bd0b2fd8 in operator() (this=<optimized out>, __ptr=0x7fc778697b80) at /usr/local/include/c++/7.3.0/bits/unique_ptr.h:78
No locals.
#20 ~unique_ptr (this=<optimized out>, __in_chrg=<optimized out>) at /usr/local/include/c++/7.3.0/bits/unique_ptr.h:268
No locals.
#21 destroy<std::unique_ptr<Checkpoint> > (this=<optimized out>, __p=<optimized out>) at /usr/local/include/c++/7.3.0/ext/new_allocator.h:140
No locals.
#22 destroy<std::unique_ptr<Checkpoint> > (__a=..., __p=<optimized out>) at /usr/local/include/c++/7.3.0/bits/alloc_traits.h:487
No locals.
#23 _M_clear (this=0x7fc770fdfb70) at /usr/local/include/c++/7.3.0/bits/list.tcc:76
        __tmp = <optimized out>
        __cur = <optimized out>
#24 ~_List_base (this=0x7fc770fdfb70, __in_chrg=<optimized out>) at /usr/local/include/c++/7.3.0/bits/stl_list.h:442
No locals.
#25 ~list (this=0x7fc770fdfb70, __in_chrg=<optimized out>) at /usr/local/include/c++/7.3.0/bits/stl_list.h:733
No locals.

#26 CheckpointManager::removeClosedUnrefCheckpoints (this=<optimized out>, vbucket=..., newOpenCheckpointCreated=newOpenCheckpointCreated@entry=@0x7fc770fdfbd5: false, limit=limit@entry=18446744073709551615)
    at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/checkpoint_manager.cc:486
        numUnrefItems = <optimized out>
---Type <return> to continue, or q <return> to quit---
        unrefCheckpointList = {<std::__cxx11::_List_base<std::unique_ptr<Checkpoint, std::default_delete<Checkpoint> >, std::allocator<std::unique_ptr<Checkpoint, std::default_delete<Checkpoint> > > >> = {
            _M_impl = {<std::allocator<std::_List_node<std::unique_ptr<Checkpoint, std::default_delete<Checkpoint> > > >> = {<__gnu_cxx::new_allocator<std::_List_node<std::unique_ptr<Checkpoint, std::default_delete<Checkpoint> > > >> = {<No data fields>}, <No data fields>}, _M_node = {<std::__detail::_List_node_base> = {_M_next = 0x7fc778358cc0, _M_prev = 0x7fc7783e1060}, _M_storage = {_M_storage = "\003\000\000\000\000\000\000"}}}}, <No data fields>}
#27 0x00007fc7bd0bd382 in CheckpointVisitor::visitBucket (this=0x7fc7b0130100, vb=...) at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/checkpoint_visitor.cc:40

        newCheckpointCreated = false
#28 0x00007fc7bd1bafbb in VBCBAdaptor::run (this=0x7fc7785b1f10) at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/kv_bucket.cc:2386
        vbid = <optimized out>
        vb = {<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 = 0x7fc77869d500, _M_refcount = {
              _M_pi = 0x7fc7786acb60}}, <No data fields>}
#29 0x00007fc7bd19fc13 in GlobalTask::execute (this=0x7fc7785b1f10) at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/globaltask.cc:74
        guard = {previous = 0x0}
#30 0x00007fc7bd199c92 in operator() (__closure=0x7fc770fe00c0) at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/folly_executorpool.cc:167
        executedAt = <optimized out>
        end = <optimized out>
        scheduleOverhead = <optimized out>
        start = {__d = {__r = 2007674230465114}}
        runAgain = false
        proxy = @0x7fc7b7673910: <error reading variable>
#31 folly::detail::function::FunctionTraits<void ()>::callSmall<FollyExecutorPool::TaskProxy::scheduleViaCPUPool()::{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:387
        fn = @0x7fc770fe00c0: {__proxy = @0x7fc7b7673910}
#32 0x00007fc7bd3191d6 in operator() (this=0x7fc770fe00c0) at /home/couchbase/jenkins/workspace/cbdeps-platform-build-old/deps/packages/build/folly/folly-prefix/src/folly/folly/Function.h:416
        fn = @0x7fc770fe00c0: {<folly::detail::function::FunctionTraits<void()>> = {<No data fields>}, data_ = {big = 0x7fc7b7673910, tiny = {
              __data = "\020\071g\267\307\177\000\000\000\000\000\000\000\000\000\000\020\071g\267\307\177", '\000' <repeats 25 times>, __align = {<No data fields>}}}, 
          call_ = 0x7fc7bd199bd0 <folly::detail::function::FunctionTraits<void ()>::callSmall<FollyExecutorPool::TaskProxy::scheduleViaCPUPool()::{lambda()#1}>(folly::detail::function::Data&)>, 
          exec_ = 0x7fc7bd197720 <folly::detail::function::execSmall<FollyExecutorPool::TaskProxy::scheduleViaCPUPool()::{lambda()#1}>(folly::detail::function::Op, folly::detail::function::Data*, folly::detail::function::Data)>}
#33 folly::ThreadPoolExecutor::runTask(std::shared_ptr<folly::ThreadPoolExecutor::Thread> const&, folly::ThreadPoolExecutor::Task&&) (this=0x7fc7a8e25400, thread=..., 
    task=<unknown type in /usr/lib/debug/opt/couchbase/lib/libep.so.debug, CU 0x3084702, DIE 0x30caaf3>)
    at /home/couchbase/jenkins/workspace/cbdeps-platform-build-old/deps/packages/build/folly/folly-prefix/src/folly/folly/executors/ThreadPoolExecutor.cpp:98
        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 = 2007674230462731}}
        stats = {expired = false, waitTime = {__r = 39862}, runTime = {__r = 0}, enqueueTime = {__d = {__r = 2007674230422869}}, requestId = 0}
#34 0x00007fc7bd3016ca in folly::CPUThreadPoolExecutor::threadRun (this=0x7fc7a8e25400, thread=...)
    at /home/couchbase/jenkins/workspace/cbdeps-platform-build-old/deps/packages/build/folly/folly-prefix/src/folly/folly/executors/CPUThreadPoolExecutor.cpp:265
        guard = {list_ = {
forbid = true, prev = 0x0, curr = {name = {static npos = <optimized out>, b_ = 0x7fc7bd38137b "CPUThreadPoolExecutor", e_ = 0x7fc7bd381390 ""}}}}
#35 0x00007fc7bd31c2f9 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.
#36 __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.
#37 __call<void, 0, 1> (__args=<optimized out>, this=<optimized out>) at /usr/local/include/c++/7.3.0/functional:467
No locals.
#38 operator()<> (this=<optimized out>) at /usr/local/include/c++/7.3.0/functional:551
No locals.
#39 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::detail::function::Data&) (p=...) at /home/couchbase/jenkins/workspace/cbdeps-platform-build-old/deps/packages/build/folly/folly-prefix/src/folly/folly/Function.h:401
        fn = <optimized out>
#40 0x00007fc7bd1980d3 in operator() (this=0x7fc7b77c24d0) at /home/couchbase/jenkins/workspace/couchbase-server-unix/server_build/tlm/deps/folly.exploded/include/folly/Function.h:416
        fn = @0x7fc7b77c24d0: <error reading variable>
#41 operator() (__closure=0x7fc7b77c24c0) at /home/couchbase/jenkins/workspace/couchbase-server-unix/server_build/tlm/deps/folly.exploded/include/folly/executors/thread_factory/PriorityThreadFactory.h:54
        func = <error reading variable func (Cannot access memory at address 0x7fc7b77c24d0)>
        priority = <error reading variable priority (Cannot access memory at address 0x7fc7b77c24c0)>
#42 folly::detail::function::FunctionTraits<void ()>::callBig<folly::PriorityThreadFactory::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 = @0x7fc7b77c24c0: <error reading variable>
#43 0x00007fc7b97c1dcf in std::execute_native_thread_routine (__p=0x7fc7a8cee6e0) at /tmp/deploy/gcc-7.3.0/libstdc++-v3/src/c++11/thread.cc:83
        __t = {_M_t = {
            _M_t = {<std::_Tuple_impl<0, std::thread::_State*, std::default_delete<std::thread::_State> >> = {<std::_Tuple_impl<1, std::default_delete<std::thread::_State> >> = {<std::_Head_base<1, std::default_delete<std::thread::_State>---Type <return> to continue, or q <return> to quit---
, true>> = {<std::default_delete<std::thread::_State>> = {<No data fields>}, <No data fields>}, <No data fields>}, <std::_Head_base<0, std::thread::_State*, false>> = {
                  _M_head_impl = 0x7fc7a8cee6e0}, <No data fields>}, <No data fields>}}}
#44 0x00007fc7b8fdadd5 in __nptl_deallocate_tsd () from /lib64/libpthread.so.0
No symbol table info available.
#45 0x00007fc770ff9700 in ?? ()
No symbol table info available.
#46 0x39409b08eebba549 in ?? ()
No symbol table info available.
#47 0x39410b0fb141a549 in ?? ()
No symbol table info available.
#48 0x0000000000000000 in ?? ()
No symbol table info available.
(gdb)