Temporarily drop gnome-dev from x86 images

See merge request Librem5/image-builder!162

It can't install due to

Librem5/librem5-base!136

so let's drop that until the package migrated.

board: Adjust to branch rename

See merge request Librem5/image-builder!161

The linux-next branch lost it's 'linux-' to avoid confusion
with upstream's linux-next tree.

Don't inherit MIRROR from environment

See merge request Librem5/image-builder!158

Increase max size of image

See merge request Librem5/image-builder!160

x86_64 qemu images are failing to build in Jenkins.

https://arm01.puri.sm/job/Images/job/Image%20Build/3568/console

    update-initramfs: Generating /boot/initrd.img-4.19.0-5-amd64
    cp: error writing '/var/tmp/mkinitramfs_urPgne//lib/udev/ata_id': No space left on device
    E: /usr/share/initramfs-tools/hooks/udev failed with return 1.
    update-initramfs: failed for /boot/initrd.img-4.19.0-5-amd64 with 1.
    dpkg: error processing package initramfs-tools (--configure):
     installed initramfs-tools package post-installation script subprocess returned error exit status 1

This commit increases the size of the virtual disk used to build the
image.

Don't inherit $MIRROR from the environment. $mirror gets overridden later
from sourced configuration in conf/dists/*

Don't try to run extlinux

See merge request Librem5/image-builder!157

This does not exist on arm64 and it's not needed.

Explicitly install vmdebootstrap/qemu-user-static on Laniakea Spark instance

See merge request Librem5/image-builder!156

build-image: Exit in case of an unknown dist

See merge request Librem5/image-builder!155

When using the spark builder setup don't carry on if the dist
is unknown.

build-image: Fix spark build condition

See merge request Librem5/image-builder!154

We want to do the setup if SPARK_ID is non-empty

Broken-by: 2db8dc7e

Install unzip in environments where it may be missing

See merge request Librem5/image-builder!108

Add Debian bullseye

See merge request Librem5/image-builder!148

No sshd

See merge request Librem5/image-builder!151

Otherwise we abort image generation due to lack of sshd.

Almost plain builds

See merge request Librem5/image-builder!150

This is supposed to build everything from the archive without
reaching out to external sources. This isn't true for uboot
yet though.

The m4.bin is already fetched in fetch_uboot().

This never worked since the fetched m4.bin is a zip archive
that was never uncompressed.

c2505d88 did only part of the job

Drop mesa from 'patched' check

See merge request Librem5/image-builder!149

Mesa tickled down into pureos-amber and from 19.3 we don't need
patches for basic funtionality anyway so let's drop that check
to make imx6 and qemu images simpler.

root.sh: Make sure we have a all package metadata

See merge request Librem5/image-builder!146

Revert "Make amber-phone images possible right now"

See merge request Librem5/image-builder!147

For things like webkit development we want the very latest so
let's allow for Debian bullseye builds as well.

This needs the security suites added when buster becomes stable.

All packages migrated now from amber-phone-staging to amber-phone.

This reverts commit 3b3b9537.

Run `apt-get update` after the installation so we fetch all
the meta data for e.g. GNOME Software. This makes a better
first impression when firering this up.

Suggested by Matthias Klumpp

Allow to specify image size

See merge request Librem5/image-builder!145

It doesn't ship with all the debug and dev packages so
let's speed up flashing.