Failure from test/format:

+ eval SEGFAULT_SIGNALS=all nice catchsegv ./t -1 -c ../../../test/format/CONFIG.stress
++ SEGFAULT_SIGNALS=all
++ nice catchsegv ./t -1 -c ../../../test/format/CONFIG.stress
t: process 27177
0x7f9b6c0282d0:./WiredTigerLog.0000000001: log record at position 297926656 has flag corruption 0x7677
0x7f9b6c0282d0:./WiredTigerLog.0000000001: log record at position 297926656 has unused[0] corruption 0x72
0x7f9b6c0282d0:./WiredTigerLog.0000000001: log record at position 297926656 has unused[1] corruption 0x71
[1532611104:313377][27177:0x7f9bcf7fe700], t, file:wt-000020.lsm, txn-recover: __log_salvageable_error, 2152: log file ./WiredTigerLog.0000000001 corrupted at position 297926656, use salvage to fix: WT_ERROR: non-specific WiredTiger error
[1532611104:313472][27177:0x7f9bcf7fe700], t, file:wt-000020.lsm, txn-recover: __wt_panic, 525: the process must exit and restart: WT_PANIC: WiredTiger library panic
[1532611104:313526][27177:0x7f9bcf7fe700], t, file:wt-000020.lsm, txn-recover: __wt_abort, 30: aborting WiredTiger library

• • • Aborted
      Register dump:

RAX: 0000000000000000 RBX: 00007f9b6c007610 RCX: ffffffffffffffff
RDX: 0000000000000006 RSI: 0000000000006a5a RDI: 0000000000006a29
RBP: 00007f9bcf7fd340 R8 : 00007f9bcf7fe700 R9 : 000000000000007a
R10: 0000000000000008 R11: 0000000000000202 R12: 00000000005b4db0
R13: 00000000005b4cfe R14: 00000000005b4cfe R15: 00000000005b4cfe
RSP: 00007f9bcf7fd1f8

RIP: 00007f9c1aee11f7 EFLAGS: 00000202

CS: 0033 FS: 0000 GS: 0000

Trap: 0000000e Error: 00000004 OldMask: 00000004 CR2: 6fea9000

FPUCW: 0000037f FPUSW: 00000000 TAG: 00007f9c
RIP: 1af57f9b RDP: cf7fcdf8

ST(0) 0000 0000000000000000 ST(1) 0000 0000000000000000
ST(2) 0000 0000000000000000 ST(3) 0000 0000000000000000
ST(4) 0000 0000000000000000 ST(5) 0000 0000000000000000
ST(6) ffff b6b3943a00000000 ST(7) 8000 8000000000000000
mxcsr: 1fa0
XMM0: 000000000000000000000000000000ff XMM1: 000000000000000000000000000000ff
XMM2: 000000000000000000000000000000ff XMM3: 000000000000000000000000000000ff
XMM4: 000000000000000000000000000000ff XMM5: 000000000000000000000000000000ff
XMM6: 000000000000000000000000000000ff XMM7: 000000000000000000000000000000ff
XMM8: 000000000000000000000000000000ff XMM9: 000000000000000000000000000000ff
XMM10: 000000000000000000000000000000ff XMM11: 000000000000000000000000000000ff
XMM12: 000000000000000000000000000000ff XMM13: 000000000000000000000000000000ff
XMM14: 000000000000000000000000000000ff XMM15: 000000000000000000000000000000ff

Backtrace:
/lib64/libc.so.6(gsignal+0x37)[0x7f9c1aee11f7]
/lib64/libc.so.6(abort+0x148)[0x7f9c1aee28e8]
/mnt/data0/jenkins/workspace/wiredtiger-test-format-stress/build_posix/../src/os_common/os_alloc.c:34(__wt_calloc)[0x454323]
/mnt/data0/jenkins/workspace/wiredtiger-test-format-stress/build_posix/../src/support/err.c:542 (discriminator 1)(__wt_panic)[0x49b0ec]
/mnt/data0/jenkins/workspace/wiredtiger-test-format-stress/build_posix/../src/log/log.c:2149(__log_salvageable_error)[0x56198b]
/mnt/data0/jenkins/workspace/wiredtiger-test-format-stress/build_posix/../src/log/log.c:2436(__wt_log_scan)[0x56248c]
/mnt/data0/jenkins/workspace/wiredtiger-test-format-stress/build_posix/../src/txn/txn_recover.c:686(__wt_txn_recover)[0x4bf7b0]
/mnt/data0/jenkins/workspace/wiredtiger-test-format-stress/build_posix/../src/conn/conn_open.c:225(__wt_connection_workers)[0x42550f]
/mnt/data0/jenkins/workspace/wiredtiger-test-format-stress/build_posix/../src/conn/conn_api.c:2720(wiredtiger_open)[0x42125c]
/mnt/data0/jenkins/workspace/wiredtiger-test-format-stress/build_posix/test/format/../../../test/format/wts.c:305(wts_open)[0x4113f0]
/mnt/data0/jenkins/workspace/wiredtiger-test-format-stress/build_posix/test/format/../../../test/format/backup.c:44(check_copy)[0x403188]
/mnt/data0/jenkins/workspace/wiredtiger-test-format-stress/build_posix/test/format/../../../test/format/backup.c:120(backup)[0x4037f4]
/lib64/libpthread.so.0(+0x7e25)[0x7f9c1b8a9e25]
/lib64/libc.so.6(clone+0x6d)[0x7f9c1afa434d]

Here's the config

+ cat RUNDIR/CONFIG
############################################

1. RUN PARAMETERS
   ############################################
   abort=0
   alter=0
   auto_throttle=1
   backups=1
   bitcnt=1
   bloom=1
   bloom_bit_count=44
   bloom_hash_count=22
   bloom_oldest=0
   cache=2001
   cache_minimum=20
   checkpoints=wiredtiger
   checkpoint_log_size=118
   checkpoint_wait=50
   checksum=on
   chunk_size=6
   compaction=0
   compression=lz4-noraw
   data_extend=0
   data_source=lsm
   delete_pct=83
   dictionary=0
   direct_io=0
   encryption=none
   evict_max=3
   file_type=row-store
   firstfit=0
   huffman_key=0
   huffman_value=0
   independent_thread_rng=0
   in_memory=0
   insert_pct=0
   internal_key_truncation=0
   internal_page_max=11
   isolation=random
   key_gap=19
   key_max=112
   key_min=23
   leaf_page_max=16
   leak_memory=0
   logging=1
   logging_archive=1
   logging_compression=none
   logging_file_max=310603
   logging_prealloc=1
   long_running_txn=0
   lsm_worker_threads=3
   merge_max=11
   mmap=1
   modify_pct=4
   ops=0
   prefix_compression=1
   prefix_compression_min=8
   prepare=0
   quiet=1
   read_pct=2
   rebalance=1
   repeat_data_pct=45
   reverse=0
   rows=1000000
   runs=1
   salvage=1
   split_pct=57
   statistics=0
   statistics_server=0
   threads=31
   timer=4
   timing_stress_checkpoint=0
   timing_stress_lookaside_sweep=0
   timing_stress_split_1=0
   timing_stress_split_2=0
   timing_stress_split_3=0
   timing_stress_split_4=0
   timing_stress_split_5=0
   timing_stress_split_6=0
   timing_stress_split_7=0
   timing_stress_split_8=0
   transaction_timestamps=0
   transaction-frequency=76
   truncate=0
   value_max=1158
   value_min=19
   verify=1
   wiredtiger_config=
   write_pct=11
   ############################################