Comment 8 for bug 1744758

This was created by:
https://libvirt.org/git/?p=libvirt.git;a=commit;h=680d2f49dad425395de627a31006cb84848cfa65

Which just is in 2.5 (that you have).
But there is an issue in that.
Later on fixed by several changes.
I had to parse through them for a while, but I think the following will fix your issue:

https://libvirt.org/git/?p=libvirt.git;a=commit;h=ba5d9dd4768f3d3d67d9eace7b6de27a2799f458
https://libvirt.org/git/?p=libvirt.git;a=commit;h=aac34eca90f37c4510b49ad85029c07c57bedb8d

That would make the detection work again fine, and due to that the feature be correctly handled again.
They apply to the last version in zesty with an offset of -4 and no complains otherwise.

This changes the .ac files, but d/rules calls --with autoreconf so I'd hope it rewrites that.
Can you give that a try in a ppa Corey?