hashicorp/nomad · error

can not diff jobs with different IDs: %q and %q

Error message

can not diff jobs with different IDs: %q and %q

What it means

Job.Diff refuses to compare two non-nil jobs whose IDs differ; diffing is only defined for two versions of the same job ID (nil on either side means added/deleted).

Source

Thrown at nomad/structs/diff.go:94

	var oldPrimitiveFlat, newPrimitiveFlat map[string]string
	filter := []string{"ID", "Status", "StatusDescription", "Version", "Stable", "CreateIndex",
		"ModifyIndex", "JobModifyIndex", "Update", "SubmitTime", "NomadTokenID", "VaultToken"}

	if j == nil && other == nil {
		return diff, nil
	} else if j == nil {
		j = &Job{}
		diff.Type = DiffTypeAdded
		newPrimitiveFlat = flatmap.Flatten(other, filter, true)
		diff.ID = other.ID
	} else if other == nil {
		other = &Job{}
		diff.Type = DiffTypeDeleted
		oldPrimitiveFlat = flatmap.Flatten(j, filter, true)
		diff.ID = j.ID
	} else {
		if j.ID != other.ID {
			return nil, fmt.Errorf("can not diff jobs with different IDs: %q and %q", j.ID, other.ID)
		}

		oldPrimitiveFlat = flatmap.Flatten(j, filter, true)
		newPrimitiveFlat = flatmap.Flatten(other, filter, true)
		diff.ID = other.ID
	}

	// Diff the primitive fields.
	diff.Fields = fieldDiffs(oldPrimitiveFlat, newPrimitiveFlat, false)

	// Datacenters diff
	if setDiff := stringSetDiff(j.Datacenters, other.Datacenters, "Datacenters", contextual); setDiff != nil && setDiff.Type != DiffTypeNone {
		diff.Objects = append(diff.Objects, setDiff)
	}

	// Constraints diff
	conDiff := primitiveObjectSetDiff(
		interfaceSlice(j.Constraints),

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Pass job versions with the same ID to Diff
2. Use nil for the old/new job to express add/delete instead of mismatched IDs

When it happens

Trigger: Thrown at nomad/structs/diff.go:94 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/664b559af6072d71. Report an issue: GitHub.