rake build fails - apt-get works erratically ( 502 connection closed [IP:127.0.0.1:3142] ) - No build artifacts were found!

Today I started over after one week of trying to get a handle on this erratic apt-get behavior. apt-get works and then suddenly gets 502 errors connection closed.

I tried without proxy, without proxy and without apt-cacher-ng. The result is always the same. So, today I removed all previous attempts sources Vagrant boxes etc.

Setting up the build environment:

# dpkg-dev added was missing.
sudo apt install \
    dpkg-dev \
    psmisc \
    git \
    rake \
    libvirt-daemon-system \
    dnsmasq-base \
    ebtables \
    faketime \
    pigz \
    qemu-system-x86 \
    qemu-utils \
    vagrant \
    vagrant-libvirt \
    vmdb2 && \
sudo systemctl restart libvirtd

for group in kvm libvirt libvirt-qemu ; do
   sudo adduser "$(whoami)" "$group"
done

git clone https://gitlab.tails.boum.org/tails/tails.git && \
 cd tails && \
 git checkout stable && \
 git submodule update --init

# Build Tails
rake build --trace 2>&1 | tee tee [PATH]build.log

My development laptop is an Acer Aspire 5 (16GB RAM, Dualcore AMD) running stock Debian Bullseye with backports enabled for the kernel and WiFi driver. No issues with the network. I have a Gibabit Internet connection.

I also tested a default Debian LiveBuild and that works without any issues.

Something is missing, but I can't figure out what it is. I attached the build.log.2022-04-25-11_20-build.log