Validator rejects aria-current="page" on a span. Correct?

[weeblrpress]

What's the issue?

If an aria-current="page" is added to a span, as can now happen with WordPress + Yoast SEO, the AMP validator invalidates the page with a The attribute 'aria-current' may not appear in tag 'span' error message.

[EDIT]: I looked up https://github.com/ampproject/amphtml/blob/master/validator/validator-main.protoascii and it appears that aria-current is simply not whitelisted.

How do we reproduce the issue?

On a WordPress install, using Yoast SEO, a page that has pagination will cause this error. Can also be reproduced by adding the aria-current attribute to any element I think.

Which AMP version is affected?

Tested as of 2017-11-17

[aghassemi]

@weeblrpress fix sent. will be in production in about 3 weeks.