Error in phase DEBIAN/40-misc and GRUB_PC/10-setup

[Thomas Lange]

First, you should read the log files.
Start with error.log:

> InRelease  Could not connect to localhost:3142 (127.0.0.1). - connect (111: Connection refused) [IP: 127.0.0.1 3142]
This is the port of the apt proxy apt-cacher-ng. You can disable using
this in sources.list.

> WARNING: These unknown packages are removed from the installation list: linux-image-amd64 initramfs-tools memtest86+ isc-dhcp-client grub-pc
Ooops. Without a kernel, you machine will not boot.

Let's look at fai.log. There you see the whole problem. You cannot
connect to the Debian package mirror.

You have to fix that. It does not make sense, that the install lcients
wants to connect localhost for a package repository. So just remove
the proxy config in sources.list.
-- 
regards Thomas