It can be tedious fixing a new module with many errors when Terraform
only outputs the first random error it encounters.
Accumulate all errors from validation, and format them for the user.
Fixes#11038
This is a **short term fix**.
Terraform core doesn't currently handle root modules named "root" well
because the prefix `[]string{"root"}` has special meaning and Terraform
core [currently] can't disambiguate between the root module and a module
named "root" in the root module.
This PR introduces a short term fix by simply disallowing root modules
named "root". This shouldn't break any BC because since 0.8.0 this
didn't work at all in many broken ways (including crashes).
Longer term, this should be fixed by removing the special prefix at all
and having empty paths be root. I started down this path but the core
changes necessary are far too scary for a patch release. We can aim for
0.9.
Fixes#4789
This improves the validation that valid provider aliases are used.
Previously, we required that provider aliases be defined in every module
they're used. This isn't correct because the alias may be used in a
parent module and inherited.
This removes that validation and creates the validation that a provider
alias must be defined in the used module or _any parent_. This allows
inheritance to work properly.
We've always had this type of validation for aliases because we believe
its a good UX tradeoff: typo-ing an alias is really painful, so we
require declaration of alias usage. It may add a small burden to
declare, but since relatively few aliases are used, it improves the
scenario where a user fat-fingers an alias name.