You mean picking it based on the facts ? It would require refactoring the whole post-test thingie so that it somehow has access to the state, or at least to the facts.
I might be able to fix my problem with a PR ;-)
According to the doc, the apt provider does support install_options. So I guess I just need to add it here.
Is there a way to change the default package provider ? https://github.com/bartavelle/language-puppet/blob/master/Puppet/NativeTypes/Package.hs#L68