+ cat CONFIG
# A reasonable configuration for stress testing.
cache_minimum=20
huffman_key=0
huffman_value=0
rows=1000000
runs=100
timer=4
timing_stress_split_1=1
timing_stress_split_2=0
timing_stress_split_3=0
timing_stress_split_4=1
timing_stress_split_5=1
timing_stress_split_6=1
timing_stress_split_7=0
+ eval nice ./t -1 -c CONFIG
++ nice ./t -1 -c CONFIG
ASAN:DEADLYSIGNAL
=================================================================
==14765==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000038 (pc 0x0000007d844d bp 0x7f786c3f0570 sp 0x7f786c3f0550 T9)
==14765==The signal is caused by a READ memory access.
==14765==Hint: address points to the zero page.
    #0 0x7d844c in __wt_page_modify_init /mnt/data0/jenkins/workspace/wiredtiger-test-race-condition-stress-sanitizer/build_posix/../src/include/btree.i:481:23
    #1 0x7ca58e in __checkpoint_tree /mnt/data0/jenkins/workspace/wiredtiger-test-race-condition-stress-sanitizer/build_posix/../src/txn/txn_ckpt.c:1627:2
    #2 0x7cb8bd in __wt_checkpoint_close /mnt/data0/jenkins/workspace/wiredtiger-test-race-condition-stress-sanitizer/build_posix/../src/txn/txn_ckpt.c:1915:9
    #3 0x58c7d2 in __wt_conn_dhandle_close /mnt/data0/jenkins/workspace/wiredtiger-test-race-condition-stress-sanitizer/build_posix/../src/conn/conn_dhandle.c:333:4
    #4 0x5a81b2 in __sweep_discard_trees /mnt/data0/jenkins/workspace/wiredtiger-test-race-condition-stress-sanitizer/build_posix/../src/conn/conn_sweep.c:175:3
    #5 0x5a62ee in __sweep_server /mnt/data0/jenkins/workspace/wiredtiger-test-race-condition-stress-sanitizer/build_posix/../src/conn/conn_sweep.c:349:3
    #6 0x7f7874532dc4 in start_thread /usr/src/debug/glibc-2.17-c758a686/nptl/pthread_create.c:308
    #7 0x7f787371976c in __clone (/lib64/libc.so.6+0xf776c)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /mnt/data0/jenkins/workspace/wiredtiger-test-race-condition-stress-sanitizer/build_posix/../src/include/btree.i:481:23 in __wt_page_modify_init
Thread T9 created by T0 here:
    #0 0x437521 in pthread_create /home/bostic/src/llvm40/projects/compiler-rt/lib/asan/asan_interceptors.cc:305
    #1 0x669090 in __wt_thread_create /mnt/data0/jenkins/workspace/wiredtiger-test-race-condition-stress-sanitizer/build_posix/../src/os_posix/os_thread.c:30:2
    #2 0x5a5a32 in __wt_sweep_create /mnt/data0/jenkins/workspace/wiredtiger-test-race-condition-stress-sanitizer/build_posix/../src/conn/conn_sweep.c:431:2
    #3 0x597e76 in __wt_connection_workers /mnt/data0/jenkins/workspace/wiredtiger-test-race-condition-stress-sanitizer/build_posix/../src/conn/conn_open.c:249:2
    #4 0x560fab in wiredtiger_open /mnt/data0/jenkins/workspace/wiredtiger-test-race-condition-stress-sanitizer/build_posix/../src/conn/conn_api.c:2761:2
    #5 0x5485a4 in wts_open /mnt/data0/jenkins/workspace/wiredtiger-test-race-condition-stress-sanitizer/build_posix/test/format/../../../test/format/wts.c:305:2
    #6 0x53cac6 in main /mnt/data0/jenkins/workspace/wiredtiger-test-race-condition-stress-sanitizer/build_posix/test/format/../../../test/format/t.c:190:3
    #7 0x7f7873643b34 in __libc_start_main /usr/src/debug/glibc-2.17-c758a686/csu/../csu/libc-start.c:274

==14765==ABORTING 

############################################
#  RUN PARAMETERS
############################################
abort=0
alter=0
auto_throttle=1
backups=0
bitcnt=2
bloom=1
bloom_bit_count=7
bloom_hash_count=20
bloom_oldest=0
cache=3497
cache_minimum=20
checkpoints=on
checkpoint_log_size=161
checkpoint_wait=81
checksum=on
chunk_size=9
compaction=0
compression=zlib-noraw
data_extend=0
data_source=lsm
delete_pct=0
dictionary=0
direct_io=0
encryption=none
evict_max=0
file_type=row-store
firstfit=0
huffman_key=0
huffman_value=0
independent_thread_rng=1
in_memory=0
insert_pct=99
internal_key_truncation=1
internal_page_max=17
isolation=random
key_gap=7
key_max=48
key_min=16
leaf_page_max=17
leak_memory=0
logging=0
logging_archive=1
logging_compression=none
logging_file_max=45392
logging_prealloc=1
long_running_txn=0
lsm_worker_threads=4
memory_page_max=9
merge_max=11
mmap=1
modify_pct=0
ops=0
prefix_compression=1
prefix_compression_min=0
prepare=0
quiet=1
read_pct=1
rebalance=1
repeat_data_pct=15
reverse=0
rows=1000000
runs=1
salvage=1
split_pct=81
statistics=0
statistics_server=0
threads=29
timer=4
timing_stress_checkpoint=0
timing_stress_lookaside_sweep=0
timing_stress_split_1=1
timing_stress_split_2=0
timing_stress_split_3=0
timing_stress_split_4=1
timing_stress_split_5=1
timing_stress_split_6=1
timing_stress_split_7=0
timing_stress_split_8=0
transaction_timestamps=0
transaction-frequency=63
truncate=0
value_max=3347
value_min=19
verify=1
wiredtiger_config=
write_pct=0
############################################