Оптимизация возврата в PHP

Я пытаюсь использовать BitBucket Pipeline с Laravel. Но каждый раз, когда запускается конвейер, выдается следующая ошибка:

> post-install-cmd: Illuminate\Foundation\ComposerScripts::postInstall
> post-install-cmd: php artisan optimize --verbose
Generating optimized class loader
Compiling common classes
Script php artisan optimize --verbose handling the post-install-cmd event returned with an error

[RuntimeException]
Error Output:

Exception trace:
() at phar:///usr/local/bin/composer/src/Composer/EventDispatcher/EventDispatcher.php:196
Composer\EventDispatcher\EventDispatcher->doDispatch() at phar:///usr/local/bin/composer/src/Composer/EventDispatcher/EventDispatcher.php:94
Composer\EventDispatcher\EventDispatcher->dispatchScript() at phar:///usr/local/bin/composer/src/Composer/Installer.php:350
Composer\Installer->run() at phar:///usr/local/bin/composer/src/Composer/Command/InstallCommand.php:134
Composer\Command\InstallCommand->execute() at phar:///usr/local/bin/composer/vendor/symfony/console/Command/Command.php:256
Symfony\Component\Console\Command\Command->run() at phar:///usr/local/bin/composer/vendor/symfony/console/Application.php:838
Symfony\Component\Console\Application->doRunCommand() at phar:///usr/local/bin/composer/vendor/symfony/console/Application.php:189
Symfony\Component\Console\Application->doRun() at phar:///usr/local/bin/composer/src/Composer/Console/Application.php:167
Composer\Console\Application->doRun() at phar:///usr/local/bin/composer/vendor/symfony/console/Application.php:120
Symfony\Component\Console\Application->run() at phar:///usr/local/bin/composer/src/Composer/Console/Application.php:98
Composer\Console\Application->run() at phar:///usr/local/bin/composer/bin/composer:43
require() at /usr/local/bin/composer:25

Bitbucket-pipelines.yml:

# This is a sample build configuration for PHP.
# Check our guides at https://confluence.atlassian.com/x/VYk8Lw for more examples.
# Only use spaces to indent your .yml configuration.
# -----
# You can specify a custom docker image from Docker Hub as your build environment.
image: phpunit/phpunit:5.0.3

pipelines:
default:
- step:
script: # Modify the commands below to build your repository.
- composer install --verbose