Installation (guix substitute) sometimes gets stuck on my Beebox mini
PC with r8169 Ethernet controller.

For the x86_64 graphical installer, I selected everything.
After it had downloaded plenty of other substitutes, installation
printed this and got stuck:

substitute: Liste der Substitute von „https://ci.guix.gnu.org“ wird aktualisiert … 100.0%
22,2 MB werden heruntergeladen
  cairo-1.16.0-doc  135KiB             616KiB/s 00:00 [##################] 100.0%

I waited 10 minutes.  Booting the installer image again, it does not
again get stuck.  Installation was successful now.  I propose this
patch, but will retry some more if installation really never freezes
with USB Ethernet.

IIRC I had had similar problems with this Ethernet socket in the past.

Note: I still need to test the patch.

Regards,
Florian