lima-vm/lima · warning

unimplemented

Error message

unimplemented

What it means

The Windows HCS driver is a skeleton: snapshot management and display/password connection features are not implemented, so every one of those driver methods returns this sentinel errUnimplemented. Seeing it means you invoked a lima feature the HCS backend does not support at all — there is no transient failure to retry.

Source

Thrown at pkg/driver/hcs/errors_windows.go:8

// SPDX-FileCopyrightText: Copyright The Lima Authors
// SPDX-License-Identifier: Apache-2.0

package hcs

import "errors"

var errUnimplemented = errors.New("unimplemented")

View on GitHub (pinned to dd909d0973)

Solutions

1. Use a driver that implements snapshots (e.g. vmType qemu or vz) for snapshot workflows
2. Skip display-password features on hcs; use the driver's native console access
3. Track lima upstream for HCS snapshot/display implementation before retrying

Example fix

// before (lima.yaml)
vmType: hcs
// after: switch to a driver with snapshot support
vmType: qemu

if inst.Config != nil && inst.Config.VMType != nil && *inst.Config.VMType == "hcs" {
	return errors.New("snapshots and display-password are unsupported on the hcs driver; use qemu or vz")
}

if err := limactl.SnapshotCreate(inst, name); err != nil {
	if strings.Contains(err.Error(), "unimplemented") {
		return fmt.Errorf("hcs driver does not support snapshots; switch vmType")
	}
	return err
}

When it happens

Trigger: limactl snapshot create/apply/delete/list, or display password / display connection operations (e.g. limactl cp/ssh with display flows, vnc password commands), dispatched to the hcs driver — the method immediately returns errUnimplemented.

Common situations: Users on Windows choosing vmType hcs (or it being auto-selected) and then attempting snapshotting or display password features that work under other drivers (qemu, vz).

Related errors

• unimplemented
• HcsCreateOperation: %w
• %s: %w
• %s: %w (result: %s)
• configuration is nil

AI-assisted analysis of lima-vm/lima@dd909d0973 (2026-09-01). Data as JSON: /api/errors/16b991308c51b95b. Report an issue: GitHub.