The error message is, for once, fairly clear - an sls is specified but
is not available.
If you examine create.sls you will see that it includes cacher.clone
Clone.sls requires and includes a state called
template-debian-10-minimal.
This is the state you are missing - NB NOT the template, but the salt
file that specifies that you have the template installed.
It looks like this:
template-debian-10-minimal:
pkg.installed:
- name: qubes-template-debian-10-minimal
- fromrepo: qubes-templates-itl
You already have files like this in
/srv/formulas/base/virtual-machines-formula/qvm for some of the other
templates.
I keep these universal requirements under /srv/salt