To reproduce:

* Install fresh Fedora 34 VM
* Compile Bitcoin Core and run `./test/functional/p2p_dns_seeds.py`
{
        allowed_syscalls.insert(__NR_access);          
        allowed_syscalls.insert(__NR_chdir);           
        allowed_syscalls.insert(__NR_chmod);           
        allowed_syscalls.insert(__NR_copy_file_range); 
        allowed_syscalls.insert(__NR_fallocate);       
        allowed_syscalls.insert(__NR_fchmod);          
        allowed_syscalls.insert(__NR_fchown);          
        allowed_syscalls.insert(__NR_fdatasync);       
        allowed_syscalls.insert(__NR_flock);           
        allowed_syscalls.insert(__NR_fstat);           
        allowed_syscalls.insert(__NR_newfstatat);      
        allowed_syscalls.insert(__NR_fsync);           
        allowed_syscalls.insert(__NR_ftruncate);       
        allowed_syscalls.insert(__NR_getcwd);          
        allowed_syscalls.insert(__NR_getdents);        
        allowed_syscalls.insert(__NR_getdents64);      
        allowed_syscalls.insert(__NR_lstat);           
        allowed_syscalls.insert(__NR_mkdir);           
        allowed_syscalls.insert(__NR_open);            
        allowed_syscalls.insert(__NR_openat);          
        allowed_syscalls.insert(__NR_readlink);        
        allowed_syscalls.insert(__NR_rename);          
        allowed_syscalls.insert(__NR_rmdir);           
        allowed_syscalls.insert(__NR_stat);            
        allowed_syscalls.insert(__NR_statfs);          
        allowed_syscalls.insert(__NR_statx);           
        allowed_syscalls.insert(__NR_unlink);          
    }
    void AllowFutex()