Unable to deploy

When I try to deploy a new version of a service which I’ve deployed many times in the past, I’m getting an error:
{ Error: EACCES: permission denied, open '~/.serverless/tracking-cache/95247d40-d54f-11e9-91a4-03ec80644c19'

Looking in ~/.serverless there’s both a cache and tracking-cache directory.

Any suggestions how I can proceed - particularly unhelpfully I’ve removed the service (that was working) to see if that helped.

The tracking-cache directory had become owned by ‘nobody’ and wasn’t writable.