hashicorp/terraform · error

workspaces not supported

Error message

workspaces not supported

What it means

A NestedBlock has a negative MinItems or MaxItems. Counts represent block occurrence limits and cannot be negative. Note the message says 'greater than zero' but the code only rejects values < 0; zero (meaning unset/unbounded) is allowed.

Solutions

1. Clamp MinItems and MaxItems to >= 0; use 0 to mean 'no limit'.
2. If you intended 'at least one', set MinItems: 1 (only valid in NestingList/NestingSet/NestingSingle).
3. Re-run InternalValidate in the provider test suite to confirm.

Example fix

// before
MinItems: required - 2, // can go negative
MaxItems: -1,
// after
MinItems: max(0, required-2),
MaxItems: 0, // 0 = unbounded

// Reject negative counts before constructing the schema.
func validCounts(min, max int) bool {
    return min >= 0 && max >= 0
}

func nonNegativeCounts(min, max int) bool { return min >= 0 && max >= 0 }

When it happens

Trigger: Setting MinItems: -1 or MaxItems: -1 on a NestedBlock, often from an arithmetic expression or a default constant that underflows. The guard at internal_validate.go:64 is `blockS.MinItems < 0 || blockS.MaxItems < 0`.

Common situations: Computing MinItems/MaxItems from a subtraction that goes negative; porting a schema where -1 was a sentinel for 'unlimited' in another system; typos in generated schema code.

Related errors

• cannot delete default state
• consul lock was lost
• failed to append certs
• missing state name
• execution halted

AI-assisted analysis of hashicorp/terraform@d32a084675 (2026-08-11). Data as JSON: /api/errors/36a249e32c021fc5. Report an issue: GitHub.

Appendix: source

Thrown at internal/backend/backend.go:37

// DefaultStateName is the name of the default, initial state that every
// backend must have. This state cannot be deleted.
const DefaultStateName = "default"

var (
	// ErrDefaultWorkspaceNotSupported is returned when an operation does not
	// support using the default workspace, but requires a named workspace to
	// be selected.
	ErrDefaultWorkspaceNotSupported = errors.New("default workspace not supported\n" +
		"You can create a new workspace with the \"workspace new\" command.")

	// ErrWorkspacesNotSupported is an error returned when a caller attempts
	// to perform an operation on a workspace other than "default" for a
	// backend that doesn't support multiple workspaces.
	//
	// The caller can detect this to do special fallback behavior or produce
	// a specific, helpful error message.
	ErrWorkspacesNotSupported = errors.New("workspaces not supported")
)

// InitFn is used to initialize a new backend.
type InitFn func() Backend

// Backend is the minimal interface that must be implemented to enable Terraform.
type Backend interface {
	// ConfigSchema returns a description of the expected configuration
	// structure for the receiving backend.
	//
	// This method does not have any side-effects for the backend and can
	// be safely used before configuring.
	ConfigSchema() *configschema.Block

	// PrepareConfig checks the validity of the values in the given
	// configuration, and inserts any missing defaults, assuming that its
	// structure has already been validated per the schema returned by
	// ConfigSchema.

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