The Timeshift author has informed me that he will fix this bug in an upstream release before the end of March.
- Bug#951302: timeshift: /mnt is used programmatically Nicholas Guriev
- Bug#951302: timeshift: /mnt is used programmatically Steve Meliza
- Bug#951302: timeshift: /mnt is used programmatically Tony George
- Bug#951302: timeshift: /mnt is used programmatically Steve Meliza