CSV import can't add records that relate to another table by anything other than id

[sxsws]

Describe the Bug

e.g. I'm importing a list of countries, which has a relation to continent. In the csv file, if I use the relation value continent.id and use the pk values of the continents, the import works fine. However, if I import by continent.title, the import fails. I have continent.title set up to not allow dupe values. This seems to cause the fail even though it isn't reported because changing the continent.title to something other than an existing record will allow an import of one record.

I guess that only the .id field value is used as a look up, whereas any other field isn't and is attempted to be inserted instead.

To Reproduce

try to import data from a csv file where the relation is using another field other than 'someRelation.id`.

Errors Shown

This file's data structure doesn't match the collection.

Which I've come to figure means lots of different things. No error shown in console.

What version of Directus are you using?

9.10.0

What version of Node.js are you using?

12.22.5

What database are you using?

mariadb

What browser are you using?

firefox

How are you deploying Directus?

local