go-delve/delve · error

unknown option %q

Error message

unknown option %q

What it means

ParseExamineMemoryArg iterates the argument list and throws this error for an option token it does not recognize while other arguments remain. The unknown token (args[0]) is reported verbatim with %q quoting.

Source

Thrown at service/api/command.go:263

			}
		case "-size":
			arg := nextArg()
			if arg == "" {
				return nil, errors.New("expected argument after -size")
			}
			var err error
			out.Size, err = strconv.ParseInt(arg, 0, 64)
			if err != nil || out.Size <= 0 || out.Size > 8 {
				return nil, errors.New("size must be a positive integer (<=8)")
			}
		case "-x":
			out.IsExpr = true
			// remaining args are going to be interpreted as expression
			out.Operand = strings.Join(args, " ")
			break loop
		default:
			if len(args) > 0 {
				return nil, fmt.Errorf("unknown option %q", args[0])
			}
			out.Operand = cmd
			break loop // only one arg left to be evaluated as a uint
		}
	}

	if len(out.Operand) == 0 {
		return nil, errors.New("no address specified")
	}

	return &out, nil
}

View on GitHub (pinned to a23773e6c3)

Solutions

1. Use only supported options: -fmt/-format, -count/-len, -x and their accepted values.
2. Remove or correct the unrecognized token reported in the error message.
3. If passing an address, give it as the final bare operand (hex/decimal literal) rather than behind a flag.

Example fix

// before
examine-memory -size 8 -x 0xc000010000
// after
examine-memory -count 8 -x 0xc000010000

var allowedOpts = map[string]bool{"-fmt": true, "-format": true, "-count": true, "-len": true, "-x": true}
// pre-scan tokens; any '-'-prefixed token not in allowedOpts will be rejected
for _, a := range tokens {
	if strings.HasPrefix(a, "-") && !allowedOpts[a] { return fmt.Errorf("unknown option %q", a) }
}

args, err := api.ParseExamineMemoryArg(argstr)
if err != nil {
	return fmt.Errorf("examine-memory rejected args: %v", err)
}

When it happens

Trigger: Calling ParseExamineMemoryArg with an unknown flag, e.g. 'examine-memory -size 8 0xc000010000' or 'examine-memory -x 0xc000010000' (-x belongs to the expression form only when recognized).

Common situations: Inventing flags like -size or -width; mixing DAP 'examineMemory' option syntax with terminal syntax; forgetting that the raw address must be the last bare argument.

Related errors

• %q is not a valid format
• illegal commandline '%s'
• %s must be followed by an argument
• unrecognized argument to %s %s
• %s %s needs to be followed by an expression

AI-assisted analysis of go-delve/delve@a23773e6c3 (2026-08-31). Data as JSON: /api/errors/d7f206582d880349. Report an issue: GitHub.