Do delete unused multipass instances

aka 'Completely stupid moves with Snapcraft #1'

You can easily fill up your drive whilst experimenting with Snapcraft if you are as wise as me.

Snapcraft (currently?) relies by default on a virtualization software also by Canonical Ltd., called Multipass.

This will seemingly thrive off pretty big files (I believe I mostly used base18 in my snaps), likely full installations of Ubuntu18. 

I would have expected nothing like to happen when I started deleting my unused multipass machines, but each took ~ 10 GB, despite being almost identical.

Most of them were just results of not caring about snap naming from the first steps ... =b

In short:

multipass list

will give you the snaps, including e.g., having forgotten to use --purge when deleting:

snapcraft-my-snap-name           Deleted           --               Not Available
snapcraft-testapp                Deleted           --               Not Available

now, at this point one might be inclined to delete and purge them well:

multipass delete snapcraft-my-snap-name --purge

and walk away happily with ~ 20 GB (or more) of free space again.