btrfs: improve an error string
@@ -54,7 +54,7 @@ func NewSnapshotter(root string) (snapshot.Snapshotter, error) {
return nil, err
}
if mnt.FSType != "btrfs" {
- return nil, fmt.Errorf("expected btrfs, got %s", mnt.FSType)
+ return nil, fmt.Errorf("path %s must be a btrfs filesystem to be used with the btrfs snapshotter", root)
}
var (
active = filepath.Join(root, "active")
