without the swapfile i get an error.
add this to your setup guide: (is from https://steemkr.com/masternode/@cliff-on-crypto/setup-arctic-coin-masternode-vps-step-by-step)

Step 2:
Run these commands to make a swapfile (for small VPS) :

sudo dd if=/dev/zero of=/var/swap.img bs=1024k count=1000
sudo mkswap /var/swap.img
sudo swapon /var/swap.img

Run free again to confirm you now have a swapfile. Note: If you chose a different server
option from Vultr, with less RAM, you’ll need a LARGER swapfile, i.e. set the count
parameter to something larger like 2048, 4096 etc. If the compilation steps fails partway
through this is usually the reason.

To make the swap file persist when the server is rebooted:

sudo chmod 0600 /var/swap.img
sudo chown root:root /var/swap.img
sudo nano /etc/fstab

Append the following line to the end of the file:

/var/swap.img none swap sw 0 0

Save the file and exit