Docker snap fails to start: /usr/bin/dockerd not present or not executable

I’m not entirely certain what’s happened here, because docker via snap was working 100% yesterday.

But today, after an apt upgrade of various packages, I get the rather innocuous message:

Jun 06 08:26:47 myitcv-virtual-machine systemd[1]: Starting LSB: Create lightweight, portable, self-sufficient containers…
Jun 06 08:26:47 myitcv-virtual-machine docker[7192]: * /usr/bin/dockerd not present or not executable
Jun 06 08:26:47 myitcv-virtual-machine systemd[1]: docker.service: Control process exited, code=exited status=1
Jun 06 08:26:47 myitcv-virtual-machine systemd[1]: docker.service: Failed with result ‘exit-code’.
Jun 06 08:26:47 myitcv-virtual-machine systemd[1]: Failed to start LSB: Create lightweight, portable, self-sufficient containers…

Any ideas?

Clearly I did something stupid because this is now working.