hashicorp/packer · error

packer error: template type should not be unset when creatin

Error message

packer error: template type should not be unset when creating a version. This is a Packer internal bug which should be reported to the development team for a fix

What it means

Internal assertion in Bucket.createVersion: the template type passed to the HCP version-creation API is TEMPLATETYPEUNSET. Packer failed to classify the template as HCL or JSON upstream — an internal bug, not a user config issue.

Source

Thrown at internal/hcp/registry/types.bucket.go:447

	// Set some version values. For Packer RunUUID should always be set.
	// Creating an version differently? Let's not overwrite a UUID that might be set.
	if bucket.Version.RunUUID == "" {
		bucket.Version.RunUUID = os.Getenv("PACKER_RUN_UUID")
	}

}

// createVersion creates an empty version for a given bucket on the HCP Packer registry.
// The version can then be stored locally and used for tracking build status and artifacts for a running
// Packer build.
func (bucket *Bucket) createVersion(
	templateType hcpPackerModels.HashicorpCloudPacker20230101TemplateType,
) (*hcpPackerModels.HashicorpCloudPacker20230101Version, error) {
	ctx := context.Background()

	if templateType == hcpPackerModels.HashicorpCloudPacker20230101TemplateTypeTEMPLATETYPEUNSET {
		return nil, fmt.Errorf(
			"packer error: template type should not be unset when creating a version. " +
				"This is a Packer internal bug which should be reported to the development team for a fix",
		)
	}

	createVersionResp, err := bucket.client.CreateVersion(
		ctx, bucket.Name, bucket.Version.Fingerprint, templateType,
	)
	if err != nil {
		return nil, fmt.Errorf("failed to create Version for Bucket %s with error: %w", bucket.Name, err)
	}

	if createVersionResp == nil {
		return nil, fmt.Errorf("failed to create Version for Bucket %s with error: %w", bucket.Name, err)
	}

	log.Println(
		"[TRACE] a valid version for build was created with the Id", createVersionResp.Payload.Version.ID,

View on GitHub (pinned to eb36e3c3e4)

Solutions

1. Report the issue to the Packer maintainers with your template and version
2. As a workaround, run with HCP disabled (HCP_PACKER_RUN_EMPTY_BUCKET off / remove registry block)

When it happens

Trigger: Thrown at internal/hcp/registry/types.bucket.go:447 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of hashicorp/packer@eb36e3c3e4 (2026-09-05). Data as JSON: /api/errors/e4d2e72bdfd85795. Report an issue: GitHub.