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_ioctl, "ioctl"},
    {__NR_ioperm, "ioperm"},
    {__NR_iopl, "iopl"},
    {__NR_ioprio_get, "ioprio_get"},
    {__NR_ioprio_set, "ioprio_set"},
    {__NR_kcmp, "kcmp"},
    {__NR_kexec_file_load, "kexec_file_load"},
    {__NR_kexec_load, "kexec_load"},
    {__NR_keyctl, "keyctl"},
    {__NR_kill, "kill"},
    {__NR_lchown, "lchown"},
    {__NR_lgetxattr, "lgetxattr"},
    {__NR_link, "link"},
    {__NR_linkat, "linkat"},
    {__NR_listen, "listen"},
    {__NR_listxattr, "listxattr"},
    {__NR_llistxattr, "llistxattr"},
    {__NR_lookup_dcookie, "lookup_dcookie"},
    {__NR_lremovexattr, "lremovexattr"},
    {__NR_lseek, "lseek"},
    {__NR_lsetxattr, "lsetxattr"},
    {__NR_lstat, "lstat"},
    {__NR_madvise, "madvise"},
    {__NR_mbind, "mbind"},
    {__NR_membarrier, "membarrier"},
    {__NR_memfd_create, "memfd_create"},
    {__NR_migrate_pages, "migrate_pages"},
    {__NR_mincore, "mincore"},
    {__NR_mkdir, "mkdir"},
    {__NR_mkdirat, "mkdirat"},