MemoryPressureMesosTest.CGROUPS_ROOT_SlaveRecovery is flaky

[----------] 1 test from MemoryPressureMesosTest
1+0 records in
1+0 records out
1048576 bytes (1.0 MB) copied, 0.000430889 s, 2.4 GB/s
[ RUN      ] MemoryPressureMesosTest.CGROUPS_ROOT_SlaveRecovery
I1202 11:09:14.319327  5062 exec.cpp:134] Version: 0.27.0
I1202 11:09:14.333317  5079 exec.cpp:208] Executor registered on slave bea15b35-9aa1-4b57-96fb-29b5f70638ac-S0
Registered executor on ubuntu
Starting task 4e62294c-cfcf-4a13-b699-c6a4b7ac5162
sh -c 'while true; do dd count=512 bs=1M if=/dev/zero of=./temp; done'
Forked command at 5085
I1202 11:09:14.391739  5077 exec.cpp:254] Received reconnect request from slave bea15b35-9aa1-4b57-96fb-29b5f70638ac-S0
I1202 11:09:14.398598  5082 exec.cpp:231] Executor re-registered on slave bea15b35-9aa1-4b57-96fb-29b5f70638ac-S0
Re-registered executor on ubuntu
Shutting down
Sending SIGTERM to process tree at pid 5085
Killing the following process trees:
[ 
-+- 5085 sh -c while true; do dd count=512 bs=1M if=/dev/zero of=./temp; done 
 \--- 5086 dd count=512 bs=1M if=/dev/zero of=./temp 
]
[       OK ] MemoryPressureMesosTest.CGROUPS_ROOT_SlaveRecovery (1096 ms)

[----------] 1 test from MemoryPressureMesosTest
1+0 records in
1+0 records out
1048576 bytes (1.0 MB) copied, 0.000404489 s, 2.6 GB/s
[ RUN      ] MemoryPressureMesosTest.CGROUPS_ROOT_SlaveRecovery
I1202 11:09:15.509950  5109 exec.cpp:134] Version: 0.27.0
I1202 11:09:15.568183  5123 exec.cpp:208] Executor registered on slave 88734acc-718e-45b0-95b9-d8f07cea8a9e-S0
Registered executor on ubuntu
Starting task 14b6bab9-9f60-4130-bdc4-44efba262bc6
Forked command at 5132
sh -c 'while true; do dd count=512 bs=1M if=/dev/zero of=./temp; done'
I1202 11:09:15.665498  5129 exec.cpp:254] Received reconnect request from slave 88734acc-718e-45b0-95b9-d8f07cea8a9e-S0
I1202 11:09:15.670995  5123 exec.cpp:381] Executor asked to shutdown
Shutting down
Sending SIGTERM to process tree at pid 5132
../../src/tests/containerizer/memory_pressure_tests.cpp:283: Failure
(usage).failure(): Unknown container: ebe90e15-72fa-4519-837b-62f43052c913
*** Aborted at 1449083355 (unix time) try "date -d @1449083355" if you are using GNU date ***