Let's say I add a validation on attachment like this `validates_attachment_size :attachment, :less_than => 10.megabytes` and if I upload a file greater than 10 megabytes then I'll get two errors in `record.errors` i.e.

```
#1: <Attachment> size must be less than 10485760 bytes
#2: <Attachment file> size must be less than 10485760 bytes.
```
Note the words inside angular brackets in both messages. One of them is attribute and the other is base_attribute. It happens because we are adding errors on both `attr_name` and `base_attr_name` i.e. `[ attr_name, base_attr_name ].each`. This should not happen.