# Terraform validate fails with "Missing required argument" after upgrading to v1.15.0 ### Terraform Version ```shell Terraform v1.15.0 ``` ### Terraform Configuration Files ### terraform/manifests/backend.tf ``` terraform { backend "azurerm" {} } ``` ### environments/stg/backend.tf (passed via -backend-config) ``` resource_group_name = "my-rg" storage_account_name = "mystorageaccount" container_name = "my-container" key = "stg.tfstate" ``` ### Debug Output https://gist.github.com/sivanesh-dsp/ee2e69ea67210ead2de282579d916a6b ### Expected Behavior `terraform validate` should pass, recognizing that backend arguments can be supplied via `-backend-config` during init (partial configuration). ### Actual Behavior ``` Error: Missing required argument on backend.tf line 2, in terraform: 2: backend "azurerm" {} The argument "storage_account_name" is required, but no definition was found. Error: Missing required argument on backend.tf line 2, in terraform: 2: backend "azurerm" {} The argument "key" is required, but no definition was found. Error: Missing required argument on backend.tf line 2, in terraform: 2: backend "azurerm" {} The argument "container_name" is required, but no definition was found. ``` ### Steps to Reproduce 1. Define a backend with an empty block: ``` terraform { backend "azurerm" {} } ``` 2. Initialize with a partial config file: ``` terraform init -backend-config=../environments/stg/backend.tf ``` whereas `backend.tf` contains: ``` resource_group_name = "my-rg" storage_account_name = "mystorageaccount" container_name = "my-container" key = "stg.tfstate" ``` 3. Run validate: ``` terraform validate ``` ### Additional Context - `terraform init` succeeds and correctly merges the backend config. - `terraform plan` works fine after successful init. - Only `validate` is affected since it checks the static block without considering the merged backend state. - The workaround is to add empty string placeholders in the backend block, which defeats the purpose of partial configuration. ### References - [#38021](https://github.com/hashicorp/terraform/pull/38021) (the PR that introduced backend validation in validate) - [Partial Configuration docs](https://developer.hashicorp.com/terraform/language/backend#partial-configuration) ### Generative AI / LLM assisted development? _No response_