After selecting netroot from the friendly menu, I do get root but no network: only the loop interface is up. This happens even though the laptop has in fact both wired and wireless net, both of which do work on the system after a normal boot.

If I run ifconfig eth0 up and dhclient eth0 on the prompt, the wired interface comes up fine, so that’s a workaround.

Bug #572426 seems to have been repurposed for something that could make this a duplicate of that. Bug #868748 also describes something similar, but this isn’t just about not getting an IP address; the interfaces (apart from lo) aren’t brough up automatically at all.