Terragrunt "version constraint ... not satisfied" in CI

By Daniel Zoghalchali·Latchkey

Your config declares terragrunt_version_constraint (or terraform_version_constraint), and the version installed on the runner does not satisfy it. Terragrunt refuses to run until the binary matches the required range.

What this error means

terragrunt stops with "The currently installed version of Terragrunt (X) is not compatible with the version constraint requiring (Y)" or the equivalent Terraform-version message.

ERRO[0000] The currently installed version of Terragrunt (v0.50.0) is not compatible with
the version constraint requiring (>= 0.55.0) as specified in terragrunt_version_constraint.

Common causes

The runner has an older or newer version than required

The install step pinned a version outside the terragrunt_version_constraint range declared in the root config.

The Terraform/OpenTofu version does not match the constraint

terraform_version_constraint requires a specific range and the binary installed by the workflow falls outside it.

How to fix it

Install a version that satisfies the constraint

1. Read the required range from the error.
2. Pin the install step to a version inside that range.
3. Confirm with terragrunt --version and terraform version.

- uses: gruntwork-io/terragrunt-action@v2
  with:
    tofu_version: 1.7.0
    tg_version: 0.55.1
    tg_command: 'run-all plan'

Update the constraint if you intend to move versions

If the new binary is deliberate, widen the constraint in the root config so it matches.

terragrunt_version_constraint = ">= 0.50.0"

How to prevent it

• Pin both Terragrunt and Terraform/OpenTofu versions in the workflow.
• Keep version constraints in the root config in sync with CI installs.
• Bump the constraint and the installed version in the same change.

Frequently asked questions

Related guides

References

• Terraform documentation
• GitHub Actions documentation