What causes "argument '-' specified without input on stdin" in Jguer/yay?

Pipe input into the command: echo "pkgname" | yay -S - or provide targets directly as arguments.

argument '-' specified without input on stdin

Error message

argument '-' specified without input on stdin

What it means

parseStdin in pkg/settings/parser/parser.go:606 handles the '-' pseudo-argument, which means 'read targets from stdin'. Before reading it checks whether stdin is a character device (an interactive terminal); if so there is no piped input, and it errors with 'argument '-' specified without input on stdin'. It exists so '-' is not silently hung waiting on terminal input.

Solutions

Pipe input into the command: echo "pkgname" | yay -S - or provide targets directly as arguments.
Remove the '-' argument if you did not intend stdin-based target reading.
In scripts, redirect stdin explicitly (cmd < filelist.txt) when using '-'.
When invoking programmatically, set cmd.Stdin to a buffer/pipe before calling Parse.

Example fix

// before
yay -S -            # run interactively, nothing on stdin
// after
echo "ripgrep" | yay -S -

Defensive patterns

Strategy: validation

Validate before calling

// Ensure '-' is only used when stdin is piped
fi, _ := os.Stdin.Stat()
piped := fi != nil && (fi.Mode()&os.ModeCharDevice) == 0
if slices.Contains(args, "-") && !piped {
    return errors.New("'-' requires piped stdin: echo pkg | cmd -")
}

Try / catch

if err := args.Parse(); err != nil {
    if strings.Contains(err.Error(), "specified without input on stdin") {
        return usageError("drop '-' or pipe targets into stdin")
    }
    return err
}

Prevention

Only use '-' when a pipe or redirection feeds stdin
In scripts, always redirect stdin explicitly when using '-'
Prefer passing target names as direct arguments in interactive use
When embedding the parser in tests/tools, wire os.Stdin to a real pipe before Parse

When it happens

Trigger: Parse() is called with the argument '-' while os.Stdin is still attached to the TTY, i.e. no pipe or redirected file is feeding stdin.

Common situations: Typing 'pacman -S -' (or yay equivalent) directly in a terminal instead of piping (e.g. 'echo pkg | pacman -S -'); running the command from a script without redirecting stdin; stdin closed/reopened incorrectly in tests or wrappers.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

AI-assisted analysis of Jguer/yay@328f4b4939 (2026-09-07). Data as JSON: /api/errors/5d7e4b5d7ee48a88. Report an issue: GitHub.

Appendix: source

Thrown at pkg/settings/parser/parser.go:606

	case hasParam(arg):
		err = a.addParam(arg, param)
		usedNext = true
	default:
		err = a.AddArg(arg)
	}

	return
}

func (a *Arguments) parseStdin() error {
	fi, err := os.Stdin.Stat()
	if err != nil {
		return err
	}

	// Ensure data is piped
	if (fi.Mode() & os.ModeCharDevice) != 0 {
		return errors.New(gotext.Get("argument '-' specified without input on stdin"))
	}

	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanLines)

	for scanner.Scan() {
		a.AddTarget(scanner.Text())
	}

	if err := scanner.Err(); err != nil {
		return err
	}

	return os.Stdin.Close()
}

func (a *Arguments) Parse() error {
	args := os.Args[1:]

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