Core was generated by `./t -c 6266'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x0000557a2627bfca in __txn_resolve_prepared_op (session=0x7ff7ef1eb278, op=0x7ff7c0136ab0, commit=false,
    cursorp=0x7ff7cfffed70) at ../src/txn/txn.c:892
892         for (; upd->txnid == WT_TXN_ABORTED; upd = upd->next)
[Current thread is 1 (Thread 0x7ff7cffff700 (LWP 22343))]
b(gdb) bt
#0  0x0000557a2627bfca in __txn_resolve_prepared_op (session=0x7ff7ef1eb278, op=0x7ff7c0136ab0, commit=false,
    cursorp=0x7ff7cfffed70) at ../src/txn/txn.c:892
#1  0x0000557a2627dc29 in __wt_txn_rollback (session=0x7ff7ef1eb278, cfg=0x7ff7cfffee10) at ../src/txn/txn.c:1651
#2  0x0000557a2625680b in __session_rollback_transaction (wt_session=0x7ff7ef1eb278, config=0x0)
    at ../src/session/session_api.c:1735
#3  0x0000557a2617be0b in rollback_transaction (tinfo=0x557a27e4c7b0) at ../../../test/format/ops.c:475
#4  0x0000557a2617d43b in ops (arg=0x557a27e4c7b0) at ../../../test/format/ops.c:991
#5  0x00007ff7ee9d36db in start_thread (arg=0x7ff7cffff700) at pthread_create.c:463
#6  0x00007ff7ee6fc88f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
(gdb) f 0
#0  0x0000557a2627bfca in __txn_resolve_prepared_op (session=0x7ff7ef1eb278, op=0x7ff7c0136ab0, commit=false,
    cursorp=0x7ff7cfffed70) at ../src/txn/txn.c:892
892         for (; upd->txnid == WT_TXN_ABORTED; upd = upd->next)

 ############################################
#  RUN PARAMETERS: V2
############################################
assert.commit_timestamp=0
assert.read_timestamp=0
backup=0
backup.incremental=off
btree.bitcnt=3
btree.compression=none
btree.dictionary=0
btree.huffman_key=1
btree.huffman_value=1
btree.internal_key_truncation=1
btree.internal_page_max=10
btree.key_gap=14
btree.key_max=57
btree.key_min=14
btree.leaf_page_max=15
btree.memory_page_max=5
btree.prefix_compression=1
btree.prefix_compression_min=1
btree.repeat_data_pct=5
btree.reverse=0
btree.split_pct=95
btree.value_max=732
btree.value_min=16
cache=77
cache.evict_max=0
cache.minimum=20
checkpoint=on
checkpoint.log_size=158
checkpoint.wait=98
disk.checksum=uncompressed
disk.data_extend=0
disk.direct_io=0
disk.encryption=none
disk.firstfit=0
disk.mmap=1
disk.mmap_all=0
format.abort=0
format.independent_thread_rng=1
format.major_timeout=0
logging=0
logging.archive=0
logging.compression=none
logging.file_max=269980
logging.prealloc=0
lsm.auto_throttle=1
lsm.bloom=1
lsm.bloom_bit_count=14
lsm.bloom_hash_count=29
lsm.bloom_oldest=0
lsm.chunk_size=1
lsm.merge_max=15
lsm.worker_threads=4
ops.alter=0
ops.compaction=0
ops.pct.delete=0
ops.pct.insert=50
ops.pct.modify=0
ops.pct.read=0
ops.pct.write=50
ops.prepare=1
ops.random_cursor=0
ops.rebalance=1
ops.salvage=1
ops.truncate=0
ops.verify=1
quiet=1
runs=1
runs.in_memory=0
runs.ops=0
runs.rows=10000
runs.source=table
runs.threads=6
runs.timer=4
runs.type=row-store
statistics=0
statistics.server=0
stress.aggressive_sweep=0
stress.checkpoint=0
stress.hs_sweep=0
stress.split_1=0
stress.split_2=0
stress.split_3=0
stress.split_4=0
stress.split_5=0
stress.split_6=0
stress.split_7=1
stress.split_8=0
transaction.frequency=100
transaction.isolation=snapshot
transaction.timestamps=1
wiredtiger.config=
wiredtiger.rwlock=1
wiredtiger.leak_memory=0
############################################