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_umask, "umask"},
    {__NR_umount2, "umount2"},
    {__NR_uname, "uname"},
    {__NR_unlink, "unlink"},
    {__NR_unlinkat, "unlinkat"},
    {__NR_unshare, "unshare"},
    {__NR_uselib, "uselib"},
    {__NR_userfaultfd, "userfaultfd"},
    {__NR_ustat, "ustat"},
    {__NR_utime, "utime"},
    {__NR_utimensat, "utimensat"},
    {__NR_utimes, "utimes"},
    {__NR_vfork, "vfork"},
    {__NR_vhangup, "vhangup"},
    {__NR_vmsplice, "vmsplice"},
    {__NR_vserver, "vserver"},
    {__NR_wait4, "wait4"},
    {__NR_waitid, "waitid"},
    {__NR_write, "write"},
    {__NR_writev, "writev"},
};
std::string GetLinuxSyscallName(uint32_t syscall_number)
{
    const auto element = LINUX_SYSCALLS.find(syscall_number);
    if (element != LINUX_SYSCALLS.end()) {
        return element->second;
    }
    return "*unknown*";
}
void SyscallSandboxDebugSignalHandler(int, siginfo_t* signal_info, void* void_signal_context)