What causes "there is no iteration associated with the channel %s" in hashicorp/packer?

Assign an iteration/release to the channel in HCP Packer before building.

there is no iteration associated with the channel %s

Error message

there is no iteration associated with the channel %s

What it means

Same family as error 40, but for the hcp-packer-iteration datasource: GetChannel succeeded yet the returned channel has a nil Iteration, meaning no iteration/release is assigned to that channel. The datasource cannot produce an iteration output and returns a null cty value.

Source

Thrown at datasource/hcp-packer-iteration/data.go:121

	log.Printf("[WARN] Deprecation: `hcp-packer-iteration` datasource has been deprecated. " +
		"Please use `hcp-packer-version` datasource instead.")
	ctx := context.TODO()

	cli, err := hcpapi.NewDeprecatedClient()
	if err != nil {
		return cty.NullVal(cty.EmptyObject), err
	}
	// Load channel.
	log.Printf("[INFO] Reading iteration info from HCP Packer registry (%s) [project_id=%s, organization_id=%s, channel=%s]",
		d.config.Bucket, cli.ProjectID, cli.OrganizationID, d.config.Channel)

	channel, err := cli.GetChannel(ctx, d.config.Bucket, d.config.Channel)
	if err != nil {
		return cty.NullVal(cty.EmptyObject), fmt.Errorf("error retrieving "+
			"iteration from HCP Packer registry: %s", err.Error())
	}
	if channel.Iteration == nil {
		return cty.NullVal(cty.EmptyObject), fmt.Errorf("there is no iteration associated with the channel %s",
			d.config.Channel)
	}

	iteration := channel.Iteration

	revokeAt := time.Time(iteration.RevokeAt)
	if !revokeAt.IsZero() && revokeAt.Before(time.Now().UTC()) {
		// If RevokeAt is not a zero date and is before NOW, it means this iteration is revoked and should not be used
		// to build new images.
		return cty.NullVal(cty.EmptyObject), fmt.Errorf("the iteration associated with the channel %s is revoked and can not be used on Packer builds",
			d.config.Channel)
	}

	output := DatasourceOutput{
		AuthorID:           iteration.AuthorID,
		BucketName:         iteration.BucketSlug,
		Complete:           iteration.Complete,
		CreatedAt:          iteration.CreatedAt.String(),

View on GitHub (pinned to eb36e3c3e4)

Solutions

Assign an iteration/release to the channel in HCP Packer before building.
Verify the channel name and that it belongs to the same bucket/project.
Query the bucket's iterations directly via the HCP UI/CLI to confirm one exists, then publish it to the channel.

Example fix

// before
data "hcp-packer-iteration" "iter" {
  bucket_name = "my-app"
  channel     = "staging" // exists but no release assigned
}
// after
// Assign a release to 'staging' in HCP, or reference a known-good channel:
data "hcp-packer-iteration" "iter" {
  bucket_name = "my-app"
  channel     = "production"
}

Defensive patterns

Strategy: validation

Validate before calling

// Confirm the channel has a release before building:
// hcp packer channels show <channel> --bucket=my-app --format=json | jq -e '.iteration' \
//   || { echo 'channel has no assigned iteration'; exit 1; }

Try / catch

packer build template.pkr.hcl 2>&1 | tee /tmp/build.log || {
  grep -q 'no iteration associated with the channel' /tmp/build.log && echo "Publish an iteration to the channel first"
  exit 1
}

Prevention

Gate channel creation and release assignment in the same pipeline step.
Verify channel state with the hcp CLI in pre-build checks.
Avoid deleting/reattaching releases during deploys while builds may run.
Share one hcp-packer-iteration lookup across templates to centralize the failure point.

When it happens

Trigger: Execute -> cli.GetChannel returns successfully but channel.Iteration == nil for d.config.Channel; Execute returns this error immediately after.

Common situations: Newly created channel with no release; release on the channel was removed or reassigned; channel name typo pointing at a different empty channel; automation cleared channel assignments during a rollback process.

Related errors

AI-assisted analysis of hashicorp/packer@eb36e3c3e4 (2026-09-05). Data as JSON: /api/errors/95d8a83a4e344d96. Report an issue: GitHub.