(gdb) bt full
#0  0x00007f1a6f10826f in operator() (b=..., a=..., __closure=0x7f1a430a2840)
    at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/paging_visitor.cc:359
        vbA = {<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 = 0x7f1a4035fb00, _M_refcount = {_M_pi = 0x7f1a403958c0}}, <No data fields>}
        vbB = {<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 = 0x7f1a2468ba00, _M_refcount = {_M_pi = 0x7f1a2469fac0}}, <No data fields>}
        aReplica = <optimized out>
        bReplica = <optimized out>
        store = <error reading variable store (Cannot access memory at address 0x7f1a430a2870)>
        pageableMemUsed = <error reading variable pageableMemUsed (Cannot access memory at address 0x7f1a430a2840)>
#1  std::_Function_handler<bool(const Vbid&, const Vbid&), PagingVisitor::getVBucketComparator() const::<lambda(const Vbid&, const Vbid&)> >::_M_invoke(const std::_Any_data &, const Vbid &, const Vbid &) (__functor=..., __args#0=..., __args#1=...) at /usr/local/include/c++/7.3.0/bits/std_function.h:302
No locals.
#2  0x00007f1a6f0f9bcc in operator() (__args#1=..., __args#0=..., this=0x7f1a257e0e00) at /usr/local/include/c++/7.3.0/bits/std_function.h:706
No locals.
#3  operator()<Vbid, std::_Deque_iterator<Vbid, Vbid&, Vbid*> > (__it=..., __val=..., this=0x7f1a257e0e00)
    at /usr/local/include/c++/7.3.0/bits/predefined_ops.h:215
No locals.
#4  __unguarded_linear_insert<std::_Deque_iterator<Vbid, Vbid&, Vbid*>, __gnu_cxx::__ops::_Val_comp_iter<std::function<bool(const Vbid&, const Vbid&)> > > (__comp=..., __last=...) at /usr/local/include/c++/7.3.0/bits/stl_algo.h:1828
        __val = {vbid = 680}
        __next = {_M_cur = 0x600000226, _M_first = 0x600000028, _M_last = <optimized out>, _M_node = 0x7f1a405043a8}
#5  __unguarded_insertion_sort<std::_Deque_iterator<Vbid, Vbid&, Vbid*>, __gnu_cxx::__ops::_Iter_comp_iter<std::function<bool(const Vbid&, const Vbid&)> > > (__comp=..., __last=..., __first=<error reading variable: access outside bounds of object referenced via synthetic pointer>)
    at /usr/local/include/c++/7.3.0/bits/stl_algo.h:1867
        __i = {_M_cur = 0x7f1a4034f9a8, _M_first = 0x7f1a4034f800, _M_last = 0x7f1a4034fa00, _M_node = 0x7f1a405043c0}
#6  std::__final_insertion_sort<std::_Deque_iterator<Vbid, Vbid&, Vbid*>, __gnu_cxx::__ops::_Iter_comp_iter<std::function<bool (Vbid const&, Vbid const&)> > >(std::_Deque_iterator<Vbid, Vbid&, Vbid*>, std::_Deque_iterator<Vbid, Vbid&, Vbid*>, __gnu_cxx::__ops::_Iter_comp_iter<std::function<bool (Vbid const&, Vbid const&)> >) (__first=..., __last=..., __comp=...) at /usr/local/include/c++/7.3.0/bits/stl_algo.h:1886
No locals.
#7  0x00007f1a6f0f1097 in __sort<std::_Deque_iterator<Vbid, Vbid&, Vbid*>, __gnu_cxx::__ops::_Iter_comp_iter<std::function<bool(const Vbid&, const Vbid&)> > > (__comp=..., __last=..., __first=...) at /usr/local/include/c++/7.3.0/bits/stl_algo.h:1971
No locals.
#8  sort<std::_Deque_iterator<Vbid, Vbid&, Vbid*>, std::function<bool(const Vbid&, const Vbid&)> > (__comp=..., __last=..., __first=...)
    at /usr/local/include/c++/7.3.0/bits/stl_algo.h:4868
No locals.
#9  VBCBAdaptor::VBCBAdaptor (this=0x7f1a42629770, s=<optimized out>, id=<optimized out>, v=..., l=<optimized out>, shutdown=<optimized out>)
    at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/kv_bucket.cc:2357
No locals.
#10 0x00007f1a6f0f148d in construct<VBCBAdaptor, KVBucket*, TaskId&, std::unique_ptr<PausableVBucketVisitor, std::default_delete<PausableVBucketVisitor> >, char const*&, bool> (this=<optimized out>, __p=0x7f1a42629770) at /usr/local/include/c++/7.3.0/ext/new_allocator.h:136
No locals.
#11 construct<VBCBAdaptor, KVBucket*, TaskId&, std::unique_ptr<PausableVBucketVisitor, std::default_delete<PausableVBucketVisitor> >, char const*&, bool---Type <return> to continue, or q <return> to quit---
> (__a=..., __p=<optimized out>) at /usr/local/include/c++/7.3.0/bits/alloc_traits.h:475
No locals.
#12 _Sp_counted_ptr_inplace<KVBucket*, TaskId&, std::unique_ptr<PausableVBucketVisitor, std::default_delete<PausableVBucketVisitor> >, char const*&, bool> (__a=..., this=<optimized out>) at /usr/local/include/c++/7.3.0/bits/shared_ptr_base.h:526
No locals.
#13 __shared_count<VBCBAdaptor, std::allocator<VBCBAdaptor>, KVBucket*, TaskId&, std::unique_ptr<PausableVBucketVisitor, std::default_delete<PausableVBucketVisitor> >, char const*&, bool> (__a=..., this=<synthetic pointer>) at /usr/local/include/c++/7.3.0/bits/shared_ptr_base.h:637
        __mem = 0x7f1a42629760
#14 __shared_ptr<std::allocator<VBCBAdaptor>, KVBucket*, TaskId&, std::unique_ptr<PausableVBucketVisitor, std::default_delete<PausableVBucketVisitor> >, char const*&, bool> (__a=..., __tag=..., this=<synthetic pointer>) at /usr/local/include/c++/7.3.0/bits/shared_ptr_base.h:1295
No locals.
#15 shared_ptr<std::allocator<VBCBAdaptor>, KVBucket*, TaskId&, std::unique_ptr<PausableVBucketVisitor, std::default_delete<PausableVBucketVisitor> >, char const*&, bool> (__a=..., __tag=..., this=<synthetic pointer>) at /usr/local/include/c++/7.3.0/bits/shared_ptr.h:344
No locals.
#16 allocate_shared<VBCBAdaptor, std::allocator<VBCBAdaptor>, KVBucket*, TaskId&, std::unique_ptr<PausableVBucketVisitor, std::default_delete<PausableVBucketVisitor> >, char const*&, bool> (__a=...) at /usr/local/include/c++/7.3.0/bits/shared_ptr.h:691
No locals.
#17 make_shared<VBCBAdaptor, KVBucket*, TaskId&, std::unique_ptr<PausableVBucketVisitor, std::default_delete<PausableVBucketVisitor> >, char const*&, bool> () at /usr/local/include/c++/7.3.0/bits/shared_ptr.h:707
No locals.
#18 KVBucket::visitAsync (this=0x7f1a4308c000, visitor=..., lbl=0x7f1a6f29be59 "Expired item remover", id=ExpiredItemPagerVisitor, 
    maxExpectedDuration=...) at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/kv_bucket.cc:2308
No locals.
#19 0x00007f1a6f0ddabd in ExpiredItemPager::run (this=0x7f1a430b26f0)
    at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/item_pager.cc:323
        phosphor_internal_category_enabled_298 = {_M_b = {_M_p = 0x0}, 
          static is_always_lock_free = <error reading variable: No global symbol "std::atomic<std::atomic<phosphor::CategoryStatus> const*>::is_always_lock_free".>}
        phosphor_internal_category_enabled_temp_298 = <optimized out>
        phosphor_internal_tpi_298 = {category = 0x33a5b3 <Address 0x33a5b3 out of bounds>, name = 0x3534a4 <Address 0x3534a4 out of bounds>, 
          type = phosphor::Complete, argument_names = {_M_elems = {0x34a079 <Address 0x34a079 out of bounds>, 
              0x34a079 <Address 0x34a079 out of bounds>}}, argument_types = {_M_elems = {phosphor::is_none, phosphor::is_none}}}
        phosphor_internal_guard_298 = {tpi = 0x7f1a6f566ec0 <ExpiredItemPager::run()::phosphor_internal_tpi_298>, enabled = true, 
          arg1 = {<No data fields>}, arg2 = {<No data fields>}, start = {__d = {__r = 2938166030038196}}}
        inverse = true
#20 0x00007f1a6f0cd0b3 in GlobalTask::execute (this=0x7f1a430b26f0)
    at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/globaltask.cc:73
        guard = {previous = 0x0}
#21 0x00007f1a6efce48f in CB3ExecutorThread::run (this=0x7f1a69bf9880)
    at /home/couchbase/jenkins/workspace/couchbase-server-unix/kv_engine/engines/ep/src/cb3_executorthread.cc:174
        curTaskDescr = {static npos = 18446744073709551615, 
          _M_dataplus = {<std::allocator<char>> = {<__gnu_cxx::new_allocator<char>> = {<No data fields>}, <No data fields>}, 
            _M_p = 0x7f1a434ad860 <Address 0x7f1a434ad860 out of bounds>}, _M_string_length = 21, {
---Type <return> to continue, or q <return> to quit---
            _M_local_buf = "\025\000\000\000\000\000\000\000pressor", _M_allocated_capacity = 21}}
        woketime = <optimized out>
        scheduleOverhead = <optimized out>
        again = <optimized out>
        runtime = <optimized out>
        q = <optimized out>
        tick = 183 '\267'
        guard = {engine = 0x0}
#22 0x00007f1a6d9ee917 in run (this=0x7f1a69b31960) at /home/couchbase/jenkins/workspace/couchbase-server-unix/platform/src/cb_pthreads.cc:58
No locals.
#23 platform_thread_wrap (arg=0x7f1a69b31960) at /home/couchbase/jenkins/workspace/couchbase-server-unix/platform/src/cb_pthreads.cc:71
        context = {_M_t = {
            _M_t = {<std::_Tuple_impl<0, CouchbaseThread*, std::default_delete<CouchbaseThread> >> = {<std::_Tuple_impl<1, std::default_delete<CouchbaseThread> >> = {<std::_Head_base<1, std::default_delete<CouchbaseThread>, true>> = {<std::default_delete<CouchbaseThread>> = {<No data fields>}, <No data fields>}, <No data fields>}, <std::_Head_base<0, CouchbaseThread*, false>> = {_M_head_impl = 0x7f1a69b31960}, <No data fields>}, <No data fields>}}}
#24 0x00007f1a6b22de65 in start_thread (arg=0x7f1a257fa700) at pthread_create.c:307
        __res = <optimized out>
        pd = 0x7f1a257fa700
        now = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {139750275000064, -1697503171757637767, 0, 8392704, 0, 139750275000064, 1604701107832586105, 
                1604855548532195193}, 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>
#25 0x00007f1a6af5688d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111
No locals.
(gdb)