This is a prototype of how the CLI layer might make use of Terraform
Core's ability to produce a partial plan if it encounters an error during
planning, with two new situations:
- When using local CLI workflow, Terraform will show the partial plan
before showing any errors.
- "terraform plan" has a new option -always-out=..., which is similar to
the existing -out=... but additionally instructs Terraform to produce
a plan file even if the plan is incomplete due to errors. This means
that the plan can still be inspected by external UI implementations.
This is just a prototype to explore how these parts might fit together.
It's not a complete implementation and so should not be shipped. In
particular, it doesn't include any mention of a plan being incomplete in
the "terraform show -json" output or in the "terraform plan -json" output,
both of which would be required for a complete solution.