There's at least one place in the devmanual that uses <uri>http:www.example.com</uri>, without a link="" attribute. Instead of fixing that example, which is currently broken, it makes more sense to support the linkless syntax so that we don't have to repeat the same URI twice.
Created attachment 598642 [details, diff] 0001-devbook.xsl-support-URIs-with-no-link-attribute.patch
Created attachment 598644 [details, diff] 0002-devbook.xsl-reindent-the-block-that-handles-uri-elem.patch Proof of concept, seems to work?
Heh, I just noticed this bug literally 2 minutes after I've filed https://github.com/gentoo/devmanual/pull/119, otherwise I'd have avoided the duplicate work.
Done by ulm.