oracle/graal · error · InvalidArgumentException

The argument '%s' could not be parsed: expected true or fals

Error message

The argument '%s' could not be parsed: expected true or false

What it means

Thrown by BooleanArgument.parseValue when the value string is not 'true' or 'false' (case-insensitive). BooleanArgument is a ValuedArgument<Boolean>, so any other spelling — 'yes', '1', 'on' — is rejected. Surfaces as InvalidArgumentException('The argument X could not be parsed: expected true or false').

Source

Thrown at compiler/src/org.graalvm.profdiff/src/org/graalvm/profdiff/args/BooleanArgument.java:42

 */
package org.graalvm.profdiff.args;

/**
 * A program argument that holds a boolean.
 */
public class BooleanArgument extends ValuedArgument<Boolean> {
    public BooleanArgument(String name, boolean defaultValue, String help) {
        super(name, defaultValue, help);
    }

    @Override
    protected Boolean parseValue(String s) throws InvalidArgumentException {
        if (s.equalsIgnoreCase("true")) {
            return true;
        } else if (s.equalsIgnoreCase("false")) {
            return false;
        } else {
            throw new InvalidArgumentException(getName(), "expected true or false");
        }
    }
}

View on GitHub (pinned to a66e9ccd1d)

Solutions

1. Use exactly 'true' or 'false' (any case) as the option value.
2. For flags declared to accept a bare '--flag' with the value in the next token, ensure the next token is not accidentally another option.
3. Audit environment variables feeding the command for 0/1/on/off values and map them to true/false.

Example fix

# before
mx profdiff normal-tier --experiment1 a --experiment2 b --percentages=falsey
# after
mx profdiff normal-tier --experiment1 a --experiment2 b --percentages=false

static boolean isBooleanArg(String s) { return s != null && (s.equalsIgnoreCase("true") || s.equalsIgnoreCase("false")); }
// gate the value before it reaches BooleanArgument.parseValue

static boolean isParsableBoolean(String s) {
    return s != null && (s.equalsIgnoreCase("true") || s.equalsIgnoreCase("false"));
}

try {
    parser.parse(args);
} catch (InvalidArgumentException e) {
    if (e.getMessage().contains("expected true or false")) { /* fix the value */ }
}

When it happens

Trigger: Passing '--someflag=1', '--someflag=yes', or an empty value '--someflag=' to any boolean option of profdiff or of a custom parser built on this args package.

Common situations: Porting shell scripts from tools that accept 0/1 or on/off for booleans; typos like 'ture'; CI variables that expand to 'Yes'.

Related errors

• no value provided
• invalid boolean value: "%s"
• Unknown option '%s'.
• The argument '%s' is required.
• The argument '%s' could not be parsed: invalid command name:

AI-assisted analysis of oracle/graal@a66e9ccd1d (2026-08-14). Data as JSON: /api/errors/bd13bc365539eab5. Report an issue: GitHub.