Seldaek/monolog · error · InvalidArgumentException

The command argument must be a non-empty string.

Error message

The command argument must be a non-empty string.

What it means

Error "The command argument must be a non-empty string." thrown in Seldaek/monolog.

Source

Thrown at src/Monolog/Handler/ProcessHandler.php:67

     * @var array<int, list<string>>
     */
    protected const DESCRIPTOR_SPEC = [
        0 => ['pipe', 'r'],  // STDIN is a pipe that the child will read from
        1 => ['pipe', 'w'],  // STDOUT is a pipe that the child will write to
        2 => ['pipe', 'w'],  // STDERR is a pipe to catch the any errors
    ];

    /**
     * @param  string                    $command Command for the process to start. Absolute paths are recommended,
     *                                            especially if you do not use the $cwd parameter.
     * @param  string|null               $cwd     "Current working directory" (CWD) for the process to be executed in.
     * @param  float                     $timeout The maximum timeout (in seconds) for the stream_select() function.
     * @throws \InvalidArgumentException
     */
    public function __construct(string $command, int|string|Level $level = Level::Debug, bool $bubble = true, ?string $cwd = null, float $timeout = 1.0)
    {
        if ($command === '') {
            throw new \InvalidArgumentException('The command argument must be a non-empty string.');
        }
        if ($cwd === '') {
            throw new \InvalidArgumentException('The optional CWD argument must be a non-empty string or null.');
        }

        parent::__construct($level, $bubble);

        $this->command = $command;
        $this->cwd = $cwd;
        $this->timeout = $timeout;
    }

    /**
     * Writes the record down to the log of the implementing handler
     *
     * @throws \UnexpectedValueException
     */
    protected function write(LogRecord $record): void

View on GitHub (pinned to 57eb102834)

When it happens

Trigger: Thrown at src/Monolog/Handler/ProcessHandler.php:67 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of Seldaek/monolog@57eb102834 (2026-08-17). Data as JSON: /api/errors/71c10dafd648d076. Report an issue: GitHub.