====== Raspberry Pi - Hybrid build environment ======
  apt-get install debootstrap qemu-user-static binfmt-support

===== Raspbian Bullseye ======
<code>
qemu-debootstrap --no-check-gpg --arch armhf bullseye /srv/raspbian-bullseye-cross/ http://archive.raspbian.org/raspbian 
mount -t proc proc /srv/raspbian-bullseye-cross/proc/
mount -t devpts devpts /srv/raspbian-bullseye-cross/dev/pts

LANG=C LC_ALL=C chroot /srv/raspbian-bullseye-cross/
cd

apt-get install perl
apt-get install dialog wget
wget http://ftp.de.debian.org/debian/pool/main/d/debian-archive-keyring/debian-archive-keyring_2021.1.1_all.deb
dpkg -i debian-archive-keyring_2021.1.1_all.deb 
rm debian-archive-keyring_2021.1.1_all.deb 

echo 'deb [arch=amd64] http://deb.debian.org/debian bullseye main' > /etc/apt/sources.list
echo '#deb [arch=amd64] https://deb.debian.org/debian-security bullseye-security main' >> /etc/apt/sources.list
echo 'deb [arch=armhf] http://archive.raspbian.org/raspbian bullseye main' >> /etc/apt/sources.list
echo 'deb [trusted=yes] http://twolife.be/raspbian/multiarchcross-bullseye/ ./' >> /etc/apt/sources.list
echo 'APT::Install-Recommends "0";' > /etc/apt/apt.conf

dpkg --add-architecture amd64
apt-get update
apt-get remove --purge gcc-7-base gcc-8-base gcc-9-base
apt-get install binutils-arm-linux-gnueabihf:amd64
apt-get install binutils

apt-get install gcc-10-arm-linux-gnueabihf g++-10-arm-linux-gnueabihf cpp-10-crosslinks g++-10-crosslinks gcc-10-crosslinks
apt-get install build-essential bash-completion mc:amd64 most:amd64 m4:amd64 bzip2:amd64 xz-utils:amd64

[hack '/var/lib/dpkg/status build-essential' (make), dpkg-dev (make)]
dpkg --purge --force-all make
dpkg -i /var/cache/apt/archives/make*amd64.deb

apt-get clean
apt-get install --purge bash:amd64 dash:amd64
apt-get install -d tar:amd64 gzip:amd64 findutils:amd64
[big hack]
</code>