It doesn't even specify which "invalid syscall".
```
$ src/bitcoind -sandbox=log-and-abort
2022-02-17T13:45:57Z Bitcoin Core version v22.99.0-b223c3c21e89 (release build)
2022-02-17T13:45:57Z Assuming ancestors of block 00000000000000000008a89e854d57e5667df88f1cdef6fde2fbca1de5b639ad have valid signatures.
2022-02-17T13:45:57Z Setting nMinimumChainWork=00000000000000000000000000000000000000001fa4663bbbe19f82de910280
2022-02-17T13:45:57Z Experimental syscall sandbox enabled (-sandbox=log-and-abort): bitcoind will terminate if an unexpected (not allowlisted) syscall is invoked.
2022-02-17T13:45:57Z Using the 'sse4(1way),sse41(4way),avx2(8way)' SHA256 implementation
2022-02-17T13:45:57Z Default data directory /…/.bitcoin
2022-02-17T13:45:57Z Using data directory /…/.bitcoin
2022-02-17T13:45:57Z Config file: /…/.bitcoin/bitcoin.conf (not found, skipping)
2022-02-17T13:45:57Z Command-line arg: sandbox="log-and-abort"
2022-02-17T13:45:57Z Using at most 125 automatic connections (1024 file descriptors available)
2022-02-17T13:45:57Z Using 16 MiB out of 32/2 requested for signature cache, able to store 524288 elements
2022-02-17T13:45:57Z Using 16 MiB out of 32/2 requested for script execution cache, able to store 524288 elements
2022-02-17T13:45:57Z Script verification uses 1 additional threads
Bad system call (core dumped)
```
Nothing in `dmesg` either.
{__NR_socketpair, "socketpair"},
    {__NR_splice, "splice"},
    {__NR_stat, "stat"},
    {__NR_statfs, "statfs"},
    {__NR_statx, "statx"},
    {__NR_swapoff, "swapoff"},
    {__NR_swapon, "swapon"},
    {__NR_symlink, "symlink"},
    {__NR_symlinkat, "symlinkat"},
    {__NR_sync, "sync"},
    {__NR_sync_file_range, "sync_file_range"},
    {__NR_syncfs, "syncfs"},
    {__NR_sysfs, "sysfs"},
    {__NR_sysinfo, "sysinfo"},
    {__NR_syslog, "syslog"},
    {__NR_tee, "tee"},
    {__NR_tgkill, "tgkill"},
    {__NR_time, "time"},
    {__NR_timer_create, "timer_create"},
    {__NR_timer_delete, "timer_delete"},
    {__NR_timer_getoverrun, "timer_getoverrun"},
    {__NR_timer_gettime, "timer_gettime"},
    {__NR_timer_settime, "timer_settime"},
    {__NR_timerfd_create, "timerfd_create"},
    {__NR_timerfd_gettime, "timerfd_gettime"},
    {__NR_timerfd_settime, "timerfd_settime"},
    {__NR_times, "times"},
    {__NR_tkill, "tkill"},
    {__NR_truncate, "truncate"},
    {__NR_tuxcall, "tuxcall"},