Seldaek/monolog · error · UnexpectedValueException

Something went wrong while selecting a stream.

Error message

Something went wrong while selecting a stream.

What it means

Error "Something went wrong while selecting a stream." thrown in Seldaek/monolog.

Source

Thrown at src/Monolog/Handler/ProcessHandler.php:131

    private function startProcess(): void
    {
        $this->process = proc_open($this->command, static::DESCRIPTOR_SPEC, $this->pipes, $this->cwd);

        foreach ($this->pipes as $pipe) {
            stream_set_blocking($pipe, false);
        }
    }

    /**
     * Selects the STDERR stream, handles upcoming startup errors, and throws an exception, if any.
     *
     * @throws \UnexpectedValueException
     */
    private function handleStartupErrors(): void
    {
        $selected = $this->selectErrorStream();
        if (false === $selected) {
            throw new \UnexpectedValueException('Something went wrong while selecting a stream.');
        }

        $errors = $this->readProcessErrors();

        if (\is_resource($this->process) === false || $errors !== '') {
            throw new \UnexpectedValueException(
                sprintf('The process "%s" could not be opened: ' . $errors, $this->command)
            );
        }
    }

    /**
     * Selects the STDERR stream.
     *
     * @return int|bool
     */
    protected function selectErrorStream()
    {

View on GitHub (pinned to 57eb102834)

When it happens

Trigger: Thrown at src/Monolog/Handler/ProcessHandler.php:131 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/821c38e66131f22b. Report an issue: GitHub.