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_clone3, "clone3"},
    {__NR_close, "close"},
    {__NR_connect, "connect"},
    {__NR_copy_file_range, "copy_file_range"},
    {__NR_creat, "creat"},
    {__NR_create_module, "create_module"},
    {__NR_delete_module, "delete_module"},
    {__NR_dup, "dup"},
    {__NR_dup2, "dup2"},
    {__NR_dup3, "dup3"},
    {__NR_epoll_create, "epoll_create"},
    {__NR_epoll_create1, "epoll_create1"},
    {__NR_epoll_ctl, "epoll_ctl"},
    {__NR_epoll_ctl_old, "epoll_ctl_old"},
    {__NR_epoll_pwait, "epoll_pwait"},
    {__NR_epoll_wait, "epoll_wait"},
    {__NR_epoll_wait_old, "epoll_wait_old"},
    {__NR_eventfd, "eventfd"},
    {__NR_eventfd2, "eventfd2"},
    {__NR_execve, "execve"},
    {__NR_execveat, "execveat"},
    {__NR_exit, "exit"},
    {__NR_exit_group, "exit_group"},
    {__NR_faccessat, "faccessat"},
    {__NR_fadvise64, "fadvise64"},
    {__NR_fallocate, "fallocate"},
    {__NR_fanotify_init, "fanotify_init"},
    {__NR_fanotify_mark, "fanotify_mark"},
    {__NR_fchdir, "fchdir"},
    {__NR_fchmod, "fchmod"},