This is a continuation of #706

The /srv/bootstrap/cache directory must be present and writable.

Env

PHP 7.2
Standard Env
Laravel 5.7

It seems that the function is_writable is called on the $manifestPath, which is set during the app startup process and isn't affected when you change the storagePath via the $app->useStoragePath() function.
I haven't found a way to forcefully change the manifest path without forking the entire laravel repo, hard coding the manifest path, and changing the composer.json to my repo.

Since the filesystem is readonly, and boostrap/cache must be writable and it is un-changeable. I've looked at the install documentation and the Git Repo for laravel, this has been the case since Laravel 5.1.

My question is, how are others getting it to work as described here?
https://github.com/GoogleCloudPlatform/php-docs-samples/tree/master/appengine/php72/laravel-framework