Fatal error: Class 'Dotenv\Dotenv' not found in ACFProInstaller/Plugin.php #17

[regenrek]

See: #17

I think this bug is still relevant!

It doesn't happen everytime but currently I'm stuck on this problem.
Here are my files (in short):

{
repositories: {
        "acf-pro": {
            "type": "package",
            "package": {
                "name": "advanced-custom-fields/advanced-custom-fields-pro",
                "type": "wordpress-plugin",
                "version" :"5.6.0",
                "dist": {
                  "type": "zip",
                  "url": "https://connect.advancedcustomfields.com/index.php?p=pro&a=download"
                },
                "require": {
                  "philippbaschke/acf-pro-installer": "^1.0",
                  "composer/installers": "^1.0"
                }
            }
        },
     }
    "require": {
        "php": "^7.0",
        "composer/installers": "~1.0",
        "oscarotero/env": "^1.0",
        "vlucas/phpdotenv": "^2.4",
        "symfony/var-dumper": "^3.3",
        "advanced-custom-fields/advanced-custom-fields-pro":"^5.6.0"
 }
}

My Command: (via Capistrano Deploy)

php composer.phar install --working-dir #{release_path} --no-dev --prefer-dist --no-interaction --optimize-autoloader --no-scripts

Output:

/usr/local/bin/php7-70STABLE-CLI /kunden/495732_2870//rp-hosting/22/49/shared/composer.phar install --working-dir /kunden/495732_2870//rp-hosting/22/49/releases/20171003092509 --no-dev --prefer-dist --no-interaction --optimize-autoloader --no-scripts stdout: Fatal error: Uncaught Error: Class 'Dotenv\Dotenv' not found in /kunden/495732_2870/rp-hosting/22/49/releases/20171003092509/vendor/philippbaschke/acf-pro-installer/src/ACFProInstaller/Plugin.php:246
Stack trace:
#0 /kunden/495732_2870/rp-hosting/22/49/releases/20171003092509/vendor/philippbaschke/acf-pro-installer/src/ACFProInstaller/Plugin.php(226): PhilippBaschke\ACFProInstaller\Plugin->loadDotEnv()
#1 /kunden/495732_2870/rp-hosting/22/49/releases/20171003092509/vendor/philippbaschke/acf-pro-installer/src/ACFProInstaller/Plugin.php(144): PhilippBaschke\ACFProInstaller\Plugin->getKeyFromEnv()
#2 [internal function]: PhilippBaschke\ACFProInstaller\Plugin->addKey(Object(Composer\Plugin\PreFileDownloadEvent))
#3 phar:///kunden/495732_2870/rp-hosting/22/49/shared/composer.phar/src/Composer/EventDispatcher/EventDispatcher.php(171): call_user_func(Array, Object(Composer\Plugin\PreFileDownloadEvent))
#4 phar:///kunden/495732_2870/rp-hosting/22/49/shared/composer.phar/src/Composer/EventDispatcher/EventDispatcher.php(81): Compos in /kunden/495732_2870/rp-hosting/22/49/releases/20171003092509/vendor/philippbaschke/acf-pro-installer/src/ACFProInstaller/Plugin.php on line 246
/usr/local/bin/php7-70STABLE-CLI /kunden/495732_2870//rp-hosting/22/49/shared/composer.phar install --working-dir /kunden/495732_2870//rp-hosting/22/49/releases/20171003092509 --no-dev --prefer-dist --no-interaction --optimize-autoloader --no-scripts stderr: Loading composer repositories with package information
Installing dependencies from lock file
Warning: The lock file is not up to date with the latest changes in composer.json. You may be getting outdated dependencies. Run update to update them.