A crash was seen while running python tests:
http://build.wiredtiger.com:8080/job/wiredtiger-test-unit-zseries/1626/console
[1511486843:326688][17813:0x3ff7e6776f0], test_bug014.test_bug014.test_bug014, WT_SESSION.rollback_transaction: __wt_delete_page_rollback, 163: 0 [1511486843:326769][17813:0x3ff7e6776f0], test_bug014.test_bug014.test_bug014, WT_SESSION.rollback_transaction: aborting WiredTiger library
Same failure is seen in Evergreen too:
https://evergreen.mongodb.com/task/wiredtiger_ubuntu1404_unit_test_dbe8848669f0d959e95bd0959eb23e88ba995161_17_11_23_11_12_23