Core was generated by `/opt/couchbase/bin/memcached -C /opt/couchbase/var/lib/couchbase/config/memcach'.
#0  0x00007f4c07e56207 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:55
55	  return INLINE_SYSCALL (tgkill, 3, pid, selftid, sig);
#0  0x00007f4c07e56207 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:55
#1  0x00007f4c07e578f8 in __GI_abort () at abort.c:90
#2  0x00007f4c089b3195 in __gnu_cxx::__verbose_terminate_handler () at /tmp/deploy/gcc-7.3.0/libstdc++-v3/libsupc++/vterminate.cc:95
#3  0x000000000054a9c2 in backtrace_terminate_handler () at /home/couchbase/jenkins/workspace/toy-unix/kv_engine/utilities/terminate_handler.cc:86
#4  0x00007f4c089b0f86 in __cxxabiv1::__terminate (handler=<optimized out>) at /tmp/deploy/gcc-7.3.0/libstdc++-v3/libsupc++/eh_terminate.cc:47
#5  0x00007f4c089b0fd1 in std::terminate () at /tmp/deploy/gcc-7.3.0/libstdc++-v3/libsupc++/eh_terminate.cc:57
#6  0x00007f4c089b1213 in __cxxabiv1::__cxa_throw (obj=obj@entry=0x7f4b94000aa0, tinfo=tinfo@entry=0x7f4c039ad2c0 <typeinfo for gsl::fail_fast>, dest=dest@entry=0x7f4c034ee140 <gsl::fail_fast::~fail_fast()>) at /tmp/deploy/gcc-7.3.0/libstdc++-v3/libsupc++/eh_throw.cc:93
#7  0x00007f4c034faf98 in gsl::fail_fast_assert (cond=<optimized out>, message=0x7f4c03700ad8 "GSL: Precondition failure at /home/couchbase/jenkins/workspace/toy-unix/kv_engine/engines/ep/src/dcp/active_stream.cc: 1321") at /home/couchbase/jenkins/workspace/toy-unix/third_party/gsl-lite/include/gsl/gsl-lite.h:473
#8  0x00007f4c0350b97b in ActiveStream::snapshot (this=this@entry=0x7f4b55dcc290, checkpointType=<optimized out>, items=std::deque with 2 elements = {...}, highCompletedSeqno=..., maxVisibleSeqno=maxVisibleSeqno@entry=1173) at /home/couchbase/jenkins/workspace/toy-unix/kv_engine/engines/ep/src/dcp/active_stream.cc:1321
#9  0x00007f4c0350e6af in ActiveStream::processItems (this=this@entry=0x7f4b55dcc290, outstandingItemsResult=..., streamMutex=...) at /home/couchbase/jenkins/workspace/toy-unix/kv_engine/engines/ep/src/dcp/active_stream.cc:1212
#10 0x00007f4c0350eb23 in ActiveStream::nextCheckpointItemTask (this=this@entry=0x7f4b55dcc290, streamMutex=...) at /home/couchbase/jenkins/workspace/toy-unix/kv_engine/engines/ep/src/dcp/active_stream.cc:932
#11 0x00007f4c0350ec04 in ActiveStream::nextCheckpointItemTask (this=0x7f4b55dcc290) at /home/couchbase/jenkins/workspace/toy-unix/kv_engine/engines/ep/src/dcp/active_stream.cc:922
#12 0x00007f4c03517eb9 in ActiveStreamCheckpointProcessorTask::run (this=0x7f4b41879990) at /home/couchbase/jenkins/workspace/toy-unix/kv_engine/engines/ep/src/dcp/active_stream_checkpoint_processor_task.cc:56
#13 0x00007f4c035c9dd4 in ExecutorThread::run (this=0x7f4c06b73920) at /home/couchbase/jenkins/workspace/toy-unix/kv_engine/engines/ep/src/executorthread.cc:190
#14 0x00007f4c0a9d9ef7 in run (this=0x7f4c06bf1c30) at /home/couchbase/jenkins/workspace/toy-unix/platform/src/cb_pthreads.cc:58
#15 platform_thread_wrap (arg=0x7f4c06bf1c30) at /home/couchbase/jenkins/workspace/toy-unix/platform/src/cb_pthreads.cc:71
#16 0x00007f4c081f4dd5 in start_thread (arg=0x7f4b8affd700) at pthread_create.c:307
#17 0x00007f4c07f1dead in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111