Improve requirements failures for composer workflow

I have also recently seen messages like Drupal core filesystem at "/var/www/html/web/core" is read only and There must be at least 10 megabytes free. mentioned in Readiness Check for Drupal Automatic Update returns errors running on DDEV testing the module in Drupal 8 via Composer installation in Lando.

I have tested the patch (#6) with a Composer install in Lando, and it works as expected, showing this text after clicking "run the readiness checks":

Your site is currently failing readiness checks for automatic updates. It cannot be automatically updated until further action is performed:
The vendor folder could not be located.

Also, I get this message if I try to enable the module from admin/modules, so that works fine as well:

Error message
This module does not currently support relocated vendor folder and composer-based workflows. (Currently using Automatic Updates version 1.x)

I am able to enable it via Drush, though:

$ drush en automatic_updates
[success] Successfully enabled: automatic_updates

I agree. Checkboxes probably can't be disabled on the module install page, like they can on on the uninstall page ... Also, it is stated very prominently that the installation fails the readiness checks.

... and thanks for all your good work on the module, like adding this feature :-)

I just tested the latest dev-version with a Drupal tar-ball in Lando, but get an error ("The website encountered an unexpected error.") if I try to enable the module ... The code in #6 patch looks different than the code which got committed in the automatic_updates.install file:

  $vendor_checker = new Vendor(\Drupal::getContainer()->get('app.root'));
  if (!empty($vendor_checker->run())) {

https://git.drupalcode.org/project/automatic_updates/blob/a5952429359dab...

The same bit in #6 patch:
if (!is_dir(\Drupal::root() . DIRECTORY_SEPARATOR . 'vendor')) {

If I change the two lines of code in the module to the single line from patch in #6, I can install the module. (It fails if I try the experimental upgrade from 8.4.7 to 8.8.0-beta, but that's another issue ...)

The error:

Message   Error: Class 'Drupal\automatic_updates\ReadinessChecker\Vendor' not found in automatic_updates_requirements() (line 17 of /app/modules/automatic_updates/automatic_updates.install) #0 [internal function]: automatic_updates_requirements('install') #1 /app/core/lib/Drupal/Core/Extension/ModuleHandler.php(392): call_user_func_array('automatic_updat...', Array) #2 /app/core/includes/install.inc(1038): Drupal\Core\Extension\ModuleHandler->invoke('automatic_updat...', 'requirements', Array) #3 /app/core/modules/system/src/Form/ModulesListForm.php(421): drupal_check_module('automatic_updat...') #4 /app/core/modules/system/src/Form/ModulesListForm.php(439): Drupal\system\Form\ModulesListForm->buildModuleList(Object(Drupal\Core\Form\FormState)) #5 [internal function]: Drupal\system\Form\ModulesListForm->submitForm(Array, Object(Drupal\Core\Form\FormState)) #6 /app/core/lib/Drupal/Core/Form/FormSubmitter.php(111): call_user_func_array(Array, Array) #7 /app/core/lib/Drupal/Core/Form/FormSubmitter.php(51): Drupal\Core\Form\FormSubmitter->executeSubmitHandlers(Array, Object(Drupal\Core\Form\FormState)) #8 /app/core/lib/Drupal/Core/Form/FormBuilder.php(590): Drupal\Core\Form\FormSubmitter->doSubmitForm(Array, Object(Drupal\Core\Form\FormState)) #9 /app/core/lib/Drupal/Core/Form/FormBuilder.php(319): Drupal\Core\Form\FormBuilder->processForm('system_modules', Array, Object(Drupal\Core\Form\FormState)) #10 /app/core/lib/Drupal/Core/Controller/FormController.php(93): Drupal\Core\Form\FormBuilder->buildForm('system_modules', Object(Drupal\Core\Form\FormState)) #11 [internal function]: Drupal\Core\Controller\FormController->getContentResult(Object(Symfony\Component\HttpFoundation\Request), Object(Drupal\Core\Routing\RouteMatch)) #12 /app/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(123): call_user_func_array(Array, Array) #13 /app/core/lib/Drupal/Core/Render/Renderer.php(582): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() #14 /app/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(124): Drupal\Core\Render\Renderer->executeInRenderContext(Object(Drupal\Core\Render\RenderContext), Object(Closure)) #15 /app/core/lib/Drupal/Core/EventSubscriber/EarlyRenderingControllerWrapperSubscriber.php(97): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array) #16 /app/vendor/symfony/http-kernel/HttpKernel.php(151): Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() #17 /app/vendor/symfony/http-kernel/HttpKernel.php(68): Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object(Symfony\Component\HttpFoundation\Request), 1) #18 /app/core/lib/Drupal/Core/StackMiddleware/Session.php(57): Symfony\Component\HttpKernel\HttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) #19 /app/core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php(47): Drupal\Core\StackMiddleware\Session->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) #20 /app/core/modules/page_cache/src/StackMiddleware/PageCache.php(106): Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) #21 /app/core/modules/page_cache/src/StackMiddleware/PageCache.php(85): Drupal\page_cache\StackMiddleware\PageCache->pass(Object(Symfony\Component\HttpFoundation\Request), 1, true) #22 /app/core/lib/Drupal/Core/StackMiddleware/ReverseProxyMiddleware.php(47): Drupal\page_cache\StackMiddleware\PageCache->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) #23 /app/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php(52): Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) #24 /app/vendor/stack/builder/src/Stack/StackedHttpKernel.php(23): Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) #25 /app/core/lib/Drupal/Core/DrupalKernel.php(693): Stack\StackedHttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true) #26 /app/index.php(19): Drupal\Core\DrupalKernel->handle(Object(Symfony\Component\HttpFoundation\Request)) #27 {main}.
Severity  

My Lando install process, for my own documentation:

mkdir drutar && cd drutar && curl -sSL https://ftp.drupal.org/files/projects/drupal-8.7.4.tar.gz | tar -xz --strip-components=1

# get latest dev-version of module
curl -sSL https://ftp.drupal.org/files/projects/automatic_updates-8.x-1.x-dev.tar.gz | tar -xz -C modules

# create Lando instance
lando init --recipe drupal8 --webroot . --name drutar

Cool, thanks. Latest version works as expected, refusing in Composer-based installation with "Error message: This module does not currently support relocated vendor folder ..." and no errors in tar-ball install, when enabling the module.