### Terraform Version ```shell Terraform v1.15.0-dev on darwin_arm64 Using a binary built from source with _experiments enabled_. ``` ### Terraform Configuration Files Note that this is hard to manually test as there are no current (i.e. active, usable) experiments enabled in the code base. Use this branch to use a version of Terraform that contains a fake experiment called `current`: https://github.com/hashicorp/terraform/tree/example-current-experiment main.tf ```terraform terraform { # empty } ``` main_override.tf ```terraform terraform { experiments = [current] } ``` ### Debug Output ``` 2025-12-15T16:05:13.984Z [INFO] Terraform version: 1.15.0 dev 2025-12-15T16:05:13.985Z [DEBUG] using github.com/hashicorp/go-tfe v1.94.0 2025-12-15T16:05:13.985Z [DEBUG] using github.com/hashicorp/hcl/v2 v2.24.0 2025-12-15T16:05:13.985Z [DEBUG] using github.com/hashicorp/terraform-svchost v0.1.1 2025-12-15T16:05:13.985Z [DEBUG] using github.com/zclconf/go-cty v1.16.3 2025-12-15T16:05:13.985Z [INFO] Go runtime version: go1.25.3 2025-12-15T16:05:13.985Z [INFO] CLI args: []string{"/Users/sarahfrench/go/src/github.com/hashicorp/terraform/__debug_bin1526299403", "-chdir=/Users/sarahfrench/tfc-test-repos/tf-manual-testing/core/pss/scratch2", "init"} 2025-12-15T16:05:13.985Z [INFO] This build of Terraform allows using experimental features 2025-12-15T16:05:13.985Z [TRACE] Stdout is a terminal of width 133 2025-12-15T16:05:13.985Z [TRACE] Stderr is a terminal of width 133 2025-12-15T16:05:13.985Z [TRACE] Stdin is a terminal 2025-12-15T16:05:13.985Z [DEBUG] Attempting to open CLI config file: /Users/sarahfrench/.terraformrc 2025-12-15T16:05:13.985Z [INFO] Loading CLI configuration from /Users/sarahfrench/.terraformrc 2025-12-15T16:05:13.985Z [INFO] Loading CLI configuration from /Users/sarahfrench/.terraform.d/credentials.tfrc.json 2025-12-15T16:05:13.986Z [DEBUG] Explicit provider installation configuration is set 2025-12-15T16:05:13.986Z [TRACE] Selected provider installation method cliconfig.ProviderInstallationFilesystemMirror("/Users/sarahfrench/tf-filesystem-mirror/") with includes [registry.terraform.io/hashicorp/pss] and excludes [] 2025-12-15T16:05:13.986Z [TRACE] Selected provider installation method cliconfig.ProviderInstallationDirect with includes [] and excludes [registry.terraform.io/hashicorp/pss] 2025-12-15T16:05:13.986Z [INFO] CLI command args: []string{"init"} ********* This is terminal output that's only present when the experiment `current` is INACTIVE. ********* Initializing the backend... 2025-12-15T16:05:16.526Z [TRACE] Meta.Backend: no config given or present on disk, so returning nil config 2025-12-15T16:05:16.526Z [TRACE] Meta.Backend: backend has not previously been initialized in this working directory 2025-12-15T16:05:16.526Z [TRACE] Meta.Backend: using default local state only (no backend configuration, and no existing initialized backend) 2025-12-15T16:05:16.526Z [TRACE] Meta.Backend: instantiated backend of type 2025-12-15T16:05:16.526Z [DEBUG] checking for provisioner in "." 2025-12-15T16:05:16.527Z [DEBUG] checking for provisioner in "/Users/sarahfrench/go/src/github.com/hashicorp/terraform" 2025-12-15T16:05:16.527Z [TRACE] Meta.Backend: backend does not support operations, so wrapping it in a local backend 2025-12-15T16:05:16.527Z [TRACE] backend/local: state manager for workspace "default" will: - read initial snapshot from terraform.tfstate - write new snapshots to terraform.tfstate - create any backup at terraform.tfstate.backup 2025-12-15T16:05:16.527Z [TRACE] statemgr.Filesystem: reading initial snapshot from terraform.tfstate 2025-12-15T16:05:16.527Z [TRACE] statemgr.Filesystem: snapshot file has nil snapshot, but that's okay 2025-12-15T16:05:16.527Z [TRACE] statemgr.Filesystem: read nil snapshot Initializing provider plugins... ╷ │ Warning: Experimental feature "current" is active │ │ on main_override.tf line 2, in terraform: │ 2: experiments = [current] │ │ Experimental features are available only in alpha releases of Terraform and are subject to breaking changes or total removal in │ later versions, based on feedback. We recommend against using experimental features in production. │ │ If you have feedback on the design of this feature, please open a GitHub issue to discuss it. │ │ (and one more similar warning elsewhere) ╵ Terraform has been successfully initialized! You may now begin working with Terraform. Try running "terraform plan" to see any changes that are required for your infrastructure. All Terraform commands should now work. If you ever set or change modules or backend configuration for Terraform, rerun this command to reinitialize your working directory. If you forget, other commands will detect it and remind you to do so if necessary. Exiting. ``` ### Expected Behavior Given that the terminal output says `Warning: Experimental feature "current" is active` I'd expect the experiment to be active. It is not active. In the branch I'm using to demonstrate this issue I added [this if...else block](https://github.com/hashicorp/terraform/commit/953c1cc3caab415df5e7a9dbd6f134d57b7a04f3) and you would expect the terminal to include the log line that indicates the experiment is active ``` ********* This is terminal output that's only present when the experiment `current` is ACTIVE. ********* ``` ### Actual Behavior Instead, the terminal output includes this: ``` ********* This is terminal output that's only present when the experiment `current` is INACTIVE. ********* ``` This shows that the warning about the active experiment is misleading, because **the experiment it isn't actually affecting Terraform's behaviour at all**. ### Steps to Reproduce 1. Build Terraform from [this branch](https://github.com/hashicorp/terraform/tree/example-current-experiment) with experiments enabled, using `go build -ldflags "-w -s -X 'main.experimentsAllowed=yes'" -o ~/go/bin/terraform-experimental` 2. Create the project using the config I shared above. 3. Run `~/go/bin/terraform-experimental init` ### Additional Context Currently when override configuration files are merged with the 'base' config the `experiments` list from the `terraform` block is ignored from all `_override.tf` files. This is why in my example above the `current` experiment doesn't cause the expected log line to be logged. I think the reason we get the warning about `Experimental feature "current" is active` is because that warning is created when we parse the override file. ### References - https://developer.hashicorp.com/terraform/language/files/override#merging-terraform-blocks - https://github.com/hashicorp/terraform/tree/example-current-experiment ### Generative AI / LLM assisted development? no.