Hi Nicolas, hello Guix! I just noticed the last update to the emacs-ivy package removed swiper.el from the package by moving from github to elpa. It seems elpa packages ivy and swiper separately (https://elpa.gnu.org/packages/swiper.html).
I don't have time to submit a patch to fix it at the moment so I'm just filing a bug, but I can get to it next week if needed :-). I think we can either go back to using github to fetch the source, or package emacs-swiper separately. WDYT? Thanks! Pierre