Ok, so just to make sure I understood your setup correctly.
You have a PXE server (DHCP + TFTP) serving the content of netboot.tar.gz with I'm guessing a kickstart/preseed value set on the kernel command line pointing to a kickstart file available on the internet?
Can you attach your /var/log/syslog from the installer environment and confirm that it's the network configuration step that's indeed failing in d-i?
Assuming you can fix your network by hand, netcat should work to send your syslog to another machine where you can then attach it to the bug.
Ok, so just to make sure I understood your setup correctly.
You have a PXE server (DHCP + TFTP) serving the content of netboot.tar.gz with I'm guessing a kickstart/preseed value set on the kernel command line pointing to a kickstart file available on the internet?
Can you attach your /var/log/syslog from the installer environment and confirm that it's the network configuration step that's indeed failing in d-i?
Assuming you can fix your network by hand, netcat should work to send your syslog to another machine where you can then attach it to the bug.