[BUG] CumulusCommunity/cumulus-vx:5.9.0 fails to deploy on Libvirt

[jbemmel]

5.10.0 (default image) works, but 5.9.0 fails with an error:

The configured shell (config.ssh.shell) is invalid and unable
to properly execute commands. The most common cause for this is
using a shell that is unavailable on the system. Please verify
you're using the full path to the shell and that the shell is
executable by the SSH user.

Not sure which variable this is, or which binary is missing

[ipspace]

According to https://developer.hashicorp.com/vagrant/docs/vagrantfile/ssh_settings#config-ssh-shell, the default shell Vagrant tries to use is bash, so it looks like they forgot to add it to the Vagrant box.

There is no way to change that to sh within netlab, you'd have to use a custom Vagrant template. See https://blog.ipspace.net/2022/06/netsim-custom-vagrant-boxes/ for details. I don't think the template search path has changed since that blog post was written, if it did please let me know (or submit a PR against https://github.com/ipspace/blog 😎)