[kevincox]

I think this is less that it is opinionated but more that the HCL evaluation feels like a pile of hacks. There are unclear rules on what can be evaluated when and what dependencies are possible. Part of this is so that `plan` can work as it does, but it seems like there are just major gaps in general. For example providers can't depend on resources. This makes it very difficult to for example set up EKS then use the kubernetes provider to manage the resources in the cluster. The solution is obviously separate stacks but that brings in a whole bunch of other problems.

I think Terraform is quite possibly the best tool available, but there are clear flaws with both the model and the implementation. I think if I were to make a Terraform v2 I would make `plan` completely pure. This would avoid the provider issues, make validation and testing in CI easier and a whole bunch of other benefits. Of course there are downsides. For example EC2 instance IDs are random so you can't just include them in your pure plan. You would need some type of placeholder that is used for evaluation. This does cause some issues as it limits the operations that you can do with that value (so you can't pick the instance size based on the random instance ID) but overall I don't think it would be a major issue if the final substitution was handled well by the framework.