This is currently behaving incorrectly when calling `trash.swift` fails
due to lack of permissions. In this instance, `trash.swift` prints
error: permissionDenied
to stdout, and this is incorrectly parsed as having successfully trashed
a file named `error` and another named ` permissionDenied`.
Let's fix this by ensuring that:
- any paths in `trashed` are in the `paths` that we wanted to trash in
the first place
- define `untrashable` by removing the `trashed` paths from `paths`
f816a39d1f