laravel/framework · warning · InvalidArgumentException

Failed to extract the request port. Ensure the log line cont

Error message

Failed to extract the request port. Ensure the log line contains a valid port: {$line}

What it means

ServeCommand::getRequestPortFromLine() parses the stdout of PHP's built-in dev server (php artisan serve) to extract the listening port. If a given log line does not match the regex capturing a port in group 2, it throws InvalidArgumentException. This is internal to the dev-server watcher and is not part of normal request handling.

Source

Thrown at src/Illuminate/Foundation/Console/ServeCommand.php:446

        preg_match($regex, $line, $matches);

        return Carbon::createFromFormat('D M d H:i:s Y', $matches[1]);
    }

    /**
     * Get the request port from the given PHP server output.
     *
     * @param  string  $line
     * @return int
     *
     * @throws \InvalidArgumentException
     */
    public static function getRequestPortFromLine($line)
    {
        preg_match('/(\[\w+\s\w+\s\d+\s[\d:]+\s\d{4}\]\s)?:(\d+)\s(?:(?:\w+$)|(?:\[.*))/', $line, $matches);

        if (! isset($matches[2])) {
            throw new \InvalidArgumentException("Failed to extract the request port. Ensure the log line contains a valid port: {$line}");
        }

        return (int) $matches[2];
    }
}

View on GitHub (pinned to e0f6eb3518)

Solutions

Update Laravel to a version whose regex matches your PHP version's server output format.
If calling getRequestPortFromLine directly, wrap it in try/catch and skip non-port lines.
For custom integrations, pre-filter lines with str_contains($line, ':') before parsing.
Pass the port explicitly via php artisan serve --port=8000 so port detection is not needed.

Example fix

// before
$port = ServeCommand::getRequestPortFromLine($line);

// after — only parse candidate lines
if (preg_match('/:\d+\s/', $line)) {
    $port = ServeCommand::getRequestPortFromLine($line);
}

Defensive patterns

Strategy: try-catch

Validate before calling

// Only invoke the parser on lines plausibly containing a port
if (preg_match('/:\d+\s/', $line)) {
    $port = ServeCommand::getRequestPortFromLine($line);
}

Type guard

function lineLooksLikeServerPortEntry(string $line): bool {
    return (bool) preg_match('/:\d+\s\S+/', $line);
}

Try / catch

try {
    $port = \Illuminate\Foundation\Console\ServeCommand::getRequestPortFromLine($line);
} catch (\InvalidArgumentException $e) {
    // not a server-port line; skip
    continue;
}

Prevention

Pass --port explicitly to artisan serve to avoid runtime detection.
Keep Laravel updated so the parser regex matches your PHP version's output.
When integrating with artisan serve output, pre-filter lines before parsing.
Treat this parser as best-effort: wrap it in try/catch for any custom usage.

When it happens

Trigger: The ServeCommand port-revealing loop calls getRequestPortFromLine() on each line of server output; if a line lacks the ':PORT ' token pattern (e.g. a PHP startup banner, an error message, or a non-conforming PHP version's output), the regex misses and the exception fires.

Common situations: Non-standard PHP CLI output format (newer/older PHP version, custom php.ini banner). A PHP warning emitted on startup before the '[date] :port' line. Manually feeding getRequestPortFromLine an arbitrary string (e.g. custom integration with artisan serve output).

Related errors

AI-assisted analysis of laravel/framework@e0f6eb3518 (2026-08-11). Data as JSON: /api/errors/387763ae07d6a6d4. Report an issue: GitHub.