What causes "requested load from stdin, but stdin is empty" in docker/cli?

Pass an input file: `docker load -i image.tar`

requested load from stdin, but stdin is empty

Error message

requested load from stdin, but stdin is empty

What it means

runLoad() defaults input to stdin. To avoid blocking forever waiting for data that will never arrive, it checks dockerCli.In().IsTerminal(): if no -i file was given and stdin is an interactive TTY (nothing piped), it errors immediately instead of hanging.

Solutions

Pass an input file: `docker load -i image.tar`
Redirect from a file: `docker load < image.tar`
Pipe from a producer command so stdin is not a TTY

Example fix

// before
docker load
// after
docker load -i image.tar
// or
docker load < image.tar

Defensive patterns

Strategy: validation

Validate before calling

if opts.input == "" && dockerCli.In().IsTerminal() {
    return errors.New("no input: pass -i <file> or pipe a tar archive on stdin")
}

Prevention

Always use -i <file> in scripts and CI for `docker load`
Redirect or pipe input rather than relying on an interactive stdin
Guard wrapper scripts with `[ -t 0 ]` to detect a missing pipe before load

When it happens

Trigger: Running `docker load` interactively in a shell with no -i flag and no input redirection.

Common situations: Forgetting to redirect a previously saved tar; running the command manually expecting a file picker.

Related errors

AI-assisted analysis of docker/cli@4f84911bfe (2026-08-07). Data as JSON: /api/errors/614fc777bfedbfbc. Report an issue: GitHub.

Appendix: source

Thrown at cli/command/image/load.go:64

	flags.StringVarP(&opts.input, "input", "i", "", "Read from tar archive file, instead of STDIN")
	flags.BoolVarP(&opts.quiet, "quiet", "q", false, "Suppress the load output")
	flags.StringSliceVar(&opts.platform, "platform", []string{}, `Load only the given platform(s). Formatted as a comma-separated list of "os[/arch[/variant]]" (e.g., "linux/amd64,linux/arm64/v8").`)
	_ = flags.SetAnnotation("platform", "version", []string{"1.48"})

	_ = cmd.RegisterFlagCompletionFunc("platform", completion.Platforms())
	return cmd
}

func runLoad(ctx context.Context, dockerCli command.Cli, opts loadOptions) error {
	var input io.Reader = dockerCli.In()

	// TODO(thaJeztah): add support for "-" as STDIN to match other commands, possibly making it a required positional argument.
	switch opts.input {
	case "":
		// To avoid getting stuck, verify that a tar file is given either in
		// the input flag or through stdin and if not display an error message and exit.
		if dockerCli.In().IsTerminal() {
			return errors.New("requested load from stdin, but stdin is empty")
		}
	default:
		// We use sequential.Open to use sequential file access on Windows, avoiding
		// depleting the standby list un-necessarily. On Linux, this equates to a regular os.Open.
		file, err := sequential.Open(opts.input)
		if err != nil {
			return err
		}
		defer func() { _ = file.Close() }()
		input = file
	}

	var options []client.ImageLoadOption
	if opts.quiet || !dockerCli.Out().IsTerminal() {
		options = append(options, client.ImageLoadWithQuiet(true))
	}

	platformList := []ocispec.Platform{}

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