abpframework/abp · warning · ArgumentException

Should specify an option name after '-' prefix!

Error message

Should specify an option name after '-' prefix!

What it means

Thrown by CommandLineArgumentParser.ParseOptionName when an argument equals exactly '-' (length <= 1). A lone hyphen is not a valid option name; the parser requires at least one character after the '-' prefix. This mirrors the '--' guard for single-dash short options.

Source

Thrown at framework/src/Volo.Abp.Cli.Core/Volo/Abp/Cli/Args/CommandLineArgumentParser.cs:101

    }

    private static string ParseOptionName(string argument)
    {
        if (argument.StartsWith("--"))
        {
            if (argument.Length <= 2)
            {
                throw new ArgumentException("Should specify an option name after '--' prefix!");
            }

            return argument.RemovePreFix("--");
        }

        if (argument.StartsWith("-"))
        {
            if (argument.Length <= 1)
            {
                throw new ArgumentException("Should specify an option name after '-' prefix!");
            }

            return argument.RemovePreFix("-");
        }

        throw new ArgumentException("Option names should start with '-' or '--'.");
    }

    private static string[] GetArgsArrayFromLine(string lineText)
    {
        var args = new List<string>();
        var currentArgBuilder = new StringBuilder();
        string currentArg = null;
        bool isInQuotes = false;
        for (int i = 0; i < lineText.Length; i++)
        {
            var c = lineText[i];
            if (c == ' ' && !isInQuotes)

View on GitHub (pinned to 7ed43b1931)

Solutions

1. Remove or correct the lone '-' token; supply the intended short option (e.g., '-v', '-h').
2. If '-' was meant as a filename/stdin marker, note the ABP CLI does not support that convention; pass an explicit path or value instead.
3. Sanitize programmatically built argument lists to drop empty or hyphen-only tokens before invoking the CLI.
4. Re-run the command with the corrected flag and verify no env var collapsed to '-' again.

Example fix

# before
abp get-source Volo.Account -
# after (remove the lone hyphen or supply the intended option)
abp get-source Volo.Account -v

// Drop lone '-' tokens before parsing.
var sanitized = args.Where(a => a != "-").ToArray();
var parsed = parser.Parse(sanitized);

public static bool IsValidOptionToken(string arg) =>
    !(arg.StartsWith("-") && !arg.StartsWith("--") && arg.Length <= 1);

try
{
    var cmd = parser.Parse(args);
}
catch (ArgumentException ex) when (ex.Message.Contains("'-' prefix", StringComparison.Ordinal))
{
    Console.Error.WriteLine($"Invalid CLI input: a bare '-' is not allowed. Args: {string.Join(' ', args)}");
    return ExitCodes.InvalidArguments;
}

When it happens

Trigger: The CLI receives a standalone '-' token, e.g., piping '-' as a flag or a shell artifact that collapses to a single hyphen. The options loop passes it to ParseOptionName which rejects it.

Common situations: Shell redirection misuse ('abp cmd -' intended as stdin); a variable that expanded to empty leaving a bare '-'; CI scripts concatenating flags where one variable was unset; typo of a short flag like intending '-v' but typing '-'.

Related errors

• Should specify an option name after '--' prefix!
• Option names should start with '-' or '--'.
• There is no template found with given name: {name}
• "public class" declaration not found!
• ERROR: Remote server returns '{response.StatusCode}'

AI-assisted analysis of abpframework/abp@7ed43b1931 (2026-08-13). Data as JSON: /api/errors/bc87f1ca79d7c1c0. Report an issue: GitHub.