WARNING: ThreadSanitizer: data race (pid=3971)
  Read of size 4 at 0x72a000004054 by thread T146 (mutexes: write M0, write M1, write M2):
    #0 __wt_log_get_backup_files /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/log/log.c:499:33 (libwiredtiger.so.12.0.0+0x566919)
    #1 __backup_log_append /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/cursor/cur_backup.c:529:9 (libwiredtiger.so.12.0.0+0x3c32b0)
    #2 __backup_start /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/cursor/cur_backup.c:872:9 (libwiredtiger.so.12.0.0+0x3bee12)
    #3 __wt_curbackup_open /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/cursor/cur_backup.c:394:9 (libwiredtiger.so.12.0.0+0x3b98d1)
    #4 __session_open_cursor_int /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/session/session_api.c:713:13 (libwiredtiger.so.12.0.0+0x7162fb)
    #5 __session_open_cursor /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/session/session_api.c:904:5 (libwiredtiger.so.12.0.0+0x719fc3)
    #6 backup /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/test/format/backup.c:575:18 (t+0xeb27c)
  Previous atomic write of size 8 at 0x72a000004050 by thread T65 (mutexes: write M3):
    #0 __wt_atomic_store_uint64_relaxed /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/include/gcc.h:398:1 (libwiredtiger.so.12.0.0+0x59fb1f)
    #1 __log_slot_close /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/log/log_slot.c:187:5 (libwiredtiger.so.12.0.0+0x5a4442)
    #2 __log_slot_switch_internal /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/log/log_slot.c:352:15 (libwiredtiger.so.12.0.0+0x5a08d8)
    #3 __wti_log_slot_switch /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/log/log_slot.c:413:9 (libwiredtiger.so.12.0.0+0x59fecf)
    #4 __wti_log_force_write /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/log/log.c:2496:13 (libwiredtiger.so.12.0.0+0x56500c)
    #5 __log_server /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/log/log_mgr.c:972:13 (libwiredtiger.so.12.0.0+0x59ba95)
  Location is heap block of size 15936 at 0x72a000004000 allocated by main thread:
    #0 calloc /data/mci/24431e4699ef584edfeef6ff4f65be5a/toolchain-builder/tmp/build-llvm-v5.sh-jKb/llvm-project-llvmorg/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:686:5 (t+0x649fb)
    #1 __wt_calloc /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/os_common/os_alloc.c:68:14 (libwiredtiger.so.12.0.0+0x5d02c4)
    #2 __wt_logmgr_create /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/log/log_mgr.c:1056:5 (libwiredtiger.so.12.0.0+0x599c9d)
    #3 __wti_connection_workers /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/conn/conn_open.c:258:5 (libwiredtiger.so.12.0.0+0x39b69a)
    #4 wiredtiger_open /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/conn/conn_api.c:3537:5 (libwiredtiger.so.12.0.0+0x332a77)
    #5 wts_open /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/test/format/wts.c:841:9 (t+0x134515)
    #6 main /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/test/format/t.c:361:9 (t+0x1249da)
  Mutex M0 (0x7fd8302b2310) created at:
    #0 pthread_mutex_init /data/mci/24431e4699ef584edfeef6ff4f65be5a/toolchain-builder/tmp/build-llvm-v5.sh-jKb/llvm-project-llvmorg/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:1327:3 (t+0x67cb3)
    #1 __wt_spin_init /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/include/mutex_inline.h:142:5 (libwiredtiger.so.12.0.0+0x752c01)
    #2 __open_session /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/session/session_api.c:2602:5 (libwiredtiger.so.12.0.0+0x71bcd0)
    #3 __wt_open_session /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/session/session_api.c:2727:5 (libwiredtiger.so.12.0.0+0x71b478)
    #4 __conn_open_session /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/conn/conn_api.c:1399:5 (libwiredtiger.so.12.0.0+0x33b662)
    #5 wt_wrap_open_session /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/test/format/format_util.c:380:5 (t+0x104262)
    #6 backup /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/test/format/backup.c:472:5 (t+0xeac5e)
  Mutex M1 (0x72940000a8e0) created at:
    #0 pthread_mutex_init /data/mci/24431e4699ef584edfeef6ff4f65be5a/toolchain-builder/tmp/build-llvm-v5.sh-jKb/llvm-project-llvmorg/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:1327:3 (t+0x67cb3)
    #1 __wt_spin_init /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/include/mutex_inline.h:142:5 (libwiredtiger.so.12.0.0+0x373711)
    #2 __wti_connection_init /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/conn/conn_handle.c:50:5 (libwiredtiger.so.12.0.0+0x3721ae)
    #3 wiredtiger_open /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/conn/conn_api.c:3120:5 (libwiredtiger.so.12.0.0+0x32e1c3)
    #4 wts_open /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/test/format/wts.c:841:9 (t+0x134515)
    #5 main /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/test/format/t.c:361:9 (t+0x1249da)
  Mutex M2 (0x72940000aa60) created at:
    #0 pthread_mutex_init /data/mci/24431e4699ef584edfeef6ff4f65be5a/toolchain-builder/tmp/build-llvm-v5.sh-jKb/llvm-project-llvmorg/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:1327:3 (t+0x67cb3)
    #1 __wt_spin_init /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/include/mutex_inline.h:142:5 (libwiredtiger.so.12.0.0+0x373711)
    #2 __wti_connection_init /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/conn/conn_handle.c:60:5 (libwiredtiger.so.12.0.0+0x372996)
    #3 wiredtiger_open /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/conn/conn_api.c:3120:5 (libwiredtiger.so.12.0.0+0x32e1c3)
    #4 wts_open /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/test/format/wts.c:841:9 (t+0x134515)
    #5 main /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/test/format/t.c:361:9 (t+0x1249da)
  Mutex M3 (0x72a000004118) created at:
    #0 pthread_mutex_init /data/mci/24431e4699ef584edfeef6ff4f65be5a/toolchain-builder/tmp/build-llvm-v5.sh-jKb/llvm-project-llvmorg/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:1327:3 (t+0x67cb3)
    #1 __wt_spin_init /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/include/mutex_inline.h:142:5 (libwiredtiger.so.12.0.0+0x59a271)
    #2 __wt_logmgr_create /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/log/log_mgr.c:1060:5 (libwiredtiger.so.12.0.0+0x599dcf)
    #3 __wti_connection_workers /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/conn/conn_open.c:258:5 (libwiredtiger.so.12.0.0+0x39b69a)
    #4 wiredtiger_open /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/conn/conn_api.c:3537:5 (libwiredtiger.so.12.0.0+0x332a77)
    #5 wts_open /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/test/format/wts.c:841:9 (t+0x134515)
    #6 main /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/test/format/t.c:361:9 (t+0x1249da)
  Thread T146 (tid=4209, running) created by main thread at:
    #0 pthread_create /data/mci/24431e4699ef584edfeef6ff4f65be5a/toolchain-builder/tmp/build-llvm-v5.sh-jKb/llvm-project-llvmorg/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:1023:3 (t+0x662e1)
    #1 __wt_thread_create /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/os_posix/os_thread.c:60:5 (libwiredtiger.so.12.0.0+0x5ecddb)
    #2 operations /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/test/format/ops.c:369:9 (t+0x108b65)
    #3 main /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/test/format/t.c:396:13 (t+0x124db0)
  Thread T65 'log-server' (tid=4038, running) created by main thread at:
    #0 pthread_create /data/mci/24431e4699ef584edfeef6ff4f65be5a/toolchain-builder/tmp/build-llvm-v5.sh-jKb/llvm-project-llvmorg/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp:1023:3 (t+0x662e1)
    #1 __wt_thread_create /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/os_posix/os_thread.c:60:5 (libwiredtiger.so.12.0.0+0x5ecddb)
    #2 __wt_logmgr_open /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/log/log_mgr.c:1157:9 (libwiredtiger.so.12.0.0+0x59ac48)
    #3 __wti_connection_workers /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/conn/conn_open.c:301:5 (libwiredtiger.so.12.0.0+0x39b94f)
    #4 wiredtiger_open /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/conn/conn_api.c:3537:5 (libwiredtiger.so.12.0.0+0x332a77)
    #5 wts_open /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/test/format/wts.c:841:9 (t+0x134515)
    #6 main /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/test/format/t.c:361:9 (t+0x1249da)

SUMMARY: ThreadSanitizer: data race /data/mci/75aef2f4b28f595470ace4f06cb275c6/wiredtiger/src/log/log.c:499:33 in __wt_log_get_backup_files

#0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
#0  __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
#1  0x00007fd84204e859 in __GI_abort () at abort.c:79
#2  0x000055eafa5cd1a7 in __interceptor_abort ()
#3  0x000055eafa5ab2bc in __sanitizer::Abort() ()
#4  0x000055eafa5a921e in __sanitizer::Die() ()
#5  0x000055eafa60e35f in __tsan::finalize(void*) ()
#6  0x00007fd8420728a7 in __run_exit_handlers (status=0, listp=0x7fd842218718 <__exit_funcs>, run_list_atexit=run_list_atexit@entry=true, run_dtors=run_dtors@entry=true) at exit.c:108
#7  0x00007fd842072a60 in __GI_exit (status=<optimized out>) at exit.c:139
#8  0x00007fd84205008a in __libc_start_main (main=0x55eafa684210 <main>, argc=8, argv=0x7fff7c64d008, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff7c64cff8) at ../csu/libc-start.c:342
#9  0x000055eafa59371e in _start ()

Adding file to tarball: 'tools/test/binary_files/mongodb_size_mismatch.log'.