Problem
Terraform Cloud automatically runs Terraform operations using the versions specified in the workspace settings. However, when the configuration’s required_version constraint conflicts with the workspace version, the run may fail before the plan begins.
Common error messages
• Error: Unsupported Terraform Core version
This configuration does not support Terraform version 1.5.7. To proceed, choose another supported version or update your configuration.
• Terraform Cloud selected version 1.4.6, but required >=1.6.0
• Runs stuck in “Pending” or “Errored” states without executing a plan.
Root Cause
This issue typically occurs due to one or more of the following conditions:
1. Hardcoded version constraints in the configuration (e.g., required_version = "~> 1.6.0") that exceed the Terraform version selected in the workspace.
2. New provider or backend features that are incompatible with older Terraform binaries used by the workspace.
3. Default workspace settings that lock Terraform to an outdated version.
4. Module-level constraints conflicting with the root module’s version requirement.
Resolution
Option 1
Update the Terraform Version
1. In Terraform Cloud, open the workspace settings.
2. Under Terraform Version, select a version that meets or exceeds your required_version.
3. Save changes and re-run your plan.
Option 2
Update the Configuration Constraint
1. Modify your configuration:
terraform {
required_version = ">= 1.4.6"
}
2. Commit and push changes to your VCS.
3. Re-trigger the run in Terraform Cloud.
Option 3
Pin to a Known Stable Version
If compatibility issues persist, pin both the configuration and workspace to a specific known-good version, such as:
terraform {
required_version = "= 1.5.7"
}
Then set the workspace Terraform version to match.