Visual studio code had an issue with file descriptors already used by the integrated terminal.
This commit asks bash to dynamically assign a "free" file descriptor to be used in the expect function.
Closes #135

It is similar to the cloud-image but it comes with a preconfigured arch
user (pw: arch) and lacks cloud-init.

host suddenly doesn't understands hostname with https://. I'm not sure
it did before, it could be DNS server doing some magic.

Reverting as this is only needed on very slow machines, and it didn't
really fix the problem, as it just fails on another line due to a
timeout.

This reverts commit ad830608.

TCG is slow and hitting the timeout under initial boot isn't uncommon.

The naming scheme has changed: archiso!74

I found that it otherwise sometimes fails to resolve in time when pacman needs it.

Will more cores make the build faster? Let's find out.

... and use readonly, local and adding a few more comments.

Running QEMU without hardware virtualization is very slow, so the
timeout is set very high.

Especially running qemu-img is very slow (the compression isn't
helping):
qemu-img convert -c -f raw -O qcow2 cloud-img.img Arch-Linux-x86_64-cloudimg-2020-08-31.qcow2

Using actual VMs to build VMs is slow and error-prone (you need to use
VNC to see what is going on, and booting takes over +110 seconds as we
wait to be sure Arch Linux is ready).

build.sh can build all three images in ~135 seconds (assuming all the
packages is cached), we still need to use a VM for the actually building
in GitLab CI (as that is the only safe way it can be done at the
moment), which is a bit slower (~22 min vs ~13 min (Packer)), but that
isn't really a big issue.

In the future we can hopefully switch to Kate Containers[1] and reduce
the build time significantly.

[1] infrastructure#108