Configurable Product Attributes that are Field instead of Dropdown

Question

I want to use an attribute I created in a configurable product. However, when I attempt to add a configurable product, and pick my attribute set, I get this notice, and this warning.

Only attributes with scope "Global", input type "Dropdown" and Use To Create Configurable Product "Yes" are available.

This attribute set does not have attributes which we can use for configurable product

Why is only Dropdown attributes allowed for configurable products, and is there a way around this. I have an alt sku attribute I want to be shown right under sku. I have been able to get around this by creating the product without the attribute in the attribute set, and then adding the attribute afterwards with no issues, but this is a hack and I'd like something more straight forward. Is there a better way to add this attribute for configurable products?

Also, is the second line really suppose to say

This attribute set has attributes which we can not use for configurable product

That would make more sense, because as is, the language suggests there's not a single attribute it can use. Is that the case?

In general, I feel I'm misunderstanding why I am unable to create my configurable product.

Answer 1

The issue isn't that all product attributes have to meet those qualifications. The issue is it must have at least one attribute that meets all those qualifications, which is what is used to reach the simple product end result based on the dropdown. The second line is correct language, however a little less than clear.