docker/cli · error

failed to save image: %w

Error message

failed to save image: %w

What it means

Error "failed to save image: %w" thrown in docker/cli.

Source

Thrown at cli/command/image/save.go:79

		if err != nil {
			return fmt.Errorf("invalid platform: %w", err)
		}
		platformList = append(platformList, pp)
	}
	if len(platformList) > 0 {
		options = append(options, client.ImageSaveWithPlatforms(platformList...))
	}

	var output io.Writer
	if opts.output == "" {
		if dockerCLI.Out().IsTerminal() {
			return errors.New("cowardly refusing to save to a terminal. Use the -o flag or redirect")
		}
		output = dockerCLI.Out()
	} else {
		writer, err := atomicwriter.New(opts.output, 0o600)
		if err != nil {
			return fmt.Errorf("failed to save image: %w", err)
		}
		defer writer.Close()
		output = writer
	}

	responseBody, err := dockerCLI.Client().ImageSave(ctx, opts.images, options...)
	if err != nil {
		return err
	}
	defer responseBody.Close()

	_, err = io.Copy(output, responseBody)
	return err
}

View on GitHub (pinned to e9452d6e78)

When it happens

Trigger: Thrown at cli/command/image/save.go:79 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of docker/cli@e9452d6e78 (2026-08-01). Data as JSON: /data/errors/d50b20b8f7ec7b86.json. Report an issue: GitHub.