memcached core dump in bucket_engine.c:1977

spoke a little too soon about the build

seeing this crash dump during regrssion on basestar-119

Thread 1 (Thread 4736):
#0 0x00007fbff149ea75 in raise () from /lib/libc.so.6
#1 0x00007fbff14a25c0 in abort () from /lib/libc.so.6
#2 0x00007fbff1497941 in __assert_fail () from /lib/libc.so.6
#3 0x00007fbff0062cd4 in bucket_engine_release_cookie (cookie=0x407a8e8)
at bucket_engine.c:1977
#4 0x00007fbfed5583f3 in TapConnMap::notifyIOThreadMain (this=0x19a1c00)
at tapconnmap.cc:441
#5 0x00007fbfed502ff2 in EventuallyPersistentEngine::notifyTapIoThread (
this=0x19a1660) at ep_engine.cc:3568
#6 0x00007fbfed508a67 in EvpNotifyTapIo (arg=0x19a1660) at ep_engine.cc:882
#7 0x00007fbff17f39ca in start_thread () from /lib/libpthread.so.0
#8 0x00007fbff15516cd in clone () from /lib/libc.so.6
#9 0x0000000000000000 in ?? ()
--------------------------------------

core logs available also attached

the core dump is pretty huge i dont think i can upload it to s3 or sth.

i will take a look tomorrow to see which test triggered this crash...