Glenn Morris <rgm@gnu.org> writes:

> Nicolas Petton wrote:
>
>> I actually do not know why adding (require 'seq) to image.el makes the
>> build fail.
>
> Files which are preloaded (ie, in loadup.el) cannot require any files
> that are not themselves in loadup (because those required files would
> then be preloaded too). This is an explicit check for such a case.

Commit c6493c6 fixes the problem, I'm closing this ticket.

Nico