Hello, I continued stabbing at the network issue, it was just a size alignment problem, so that depending on their sizes, half of the network packets would be discarded by mach_msg. Hurd-amd64 packages are getting rebuilt to contain the fix.
The issue I'm still seeing now is that I cannot get to install some packages, such as libicu72. When I pass it as extra package to debootstrap, it does get installed, but when I "dpkg -i" it by hand, things halt. And there is still the 64bit change proposed proposed by Flavio that needs to get reviewed. Samuel