GuixSD stops on booting process after upgrades

[znavko]

Hello! I cannot give you exact info. The description of a problem I usually meet  is this.

After guix has updated kernel with `guix pull` or `guix system reconfigure /etc/config.scm` and I reboot. Boot up process stops with no any errors on any line without matter. Not every update this occurs, but sometimes.

So I reboot and it goes ok. Today I rebooted three times before it started to boot properly. I think my new usb bluetooth mouse was the reason, cause guix stopped after line 'usb mouse detected'.  I've just unplagged it some new line occurs about mouse was disconnected, and I reboot. And guixsd booted ok.

Please, is this a kind of initialization process after kernel update and need just to wait? Or is it a bug?