There's a lot of advice online showing how to get rid of snap. (e.g.: https://cialu.net/how-to-disable-and-remove-completely-snaps-in-ubuntu-linux/ worked for me) so the only result (so far, a few months later) is that Chromium has lost a user, and having upgraded Ubuntu since the original Warty, if snap becomes obligatory I'll have to take a look at Mint, or Devuan.

Thank you, but this answers the question and means I will be unable to use svelte.