Logging not working after setup:di:compile

[erikhansen]

Steps to reproduce

1. Install the AvaTax extension.
2. Compile using: bin/magento setup:di:compile
3. Any actions that trigger the AvaTax code will result in this error "$serverData must be an array or object implementing ArrayAccess":

Overview of issue

This issue is being caused because the \ClassyLlama\AvaTax\Model\Logger\FileHandler and \ClassyLlama\AvaTax\Model\Logger\DbHandler classes are getting the \Monolog\Processor\WebProcessor class via dependency injection. However whenever Magento \Magento\Framework\ObjectManager\Config\Compiled::getArguments method is called to get the constructor arguments for the \Monolog\Processor\WebProcessor class, since that class doesn't have any arguments specified in di.xml, the WebProcessor class defaults to getting a single argument which is an instance of Magento\Framework\ObjectManagerInterface (see https://github.com/magento/magento2/blob/2.0.6/lib/internal/Magento/Framework/ObjectManager/Config/Compiled.php#L79)

NOTE: This issue hasn't been detected before as Magento has recommended against using the bin/magento setup:di:compile due to issues with it ("There is a known issue with the single-tenant compiler; it does not currently compile proxies. Therefore, if you're preparing to deploy to production, you must use the multi-tenant compiler."), so testing wasn't being done using that compilation method.

[erfanimani]

I came across this issue, and another way to solve it is to create a virtualType with null arguments for the web processor:

<virtualType name="MyWebProcessor" type="Monolog\Processor\WebProcessor">
    <arguments>
        <argument name="serverData" xsi:type="null"></argument>
        <argument name="extraFields" xsi:type="null"></argument>
    </arguments>
</virtualType>

[erikhansen]

@erfanimani Would you be interested in submitting a PR to resolve this issue?

[erfanimani]

My bad @erikhansen — I came across the same root issue, but not in this specific module :)

(This issue comes up #1 for the search "$serverData must be an array or object implementing ArrayAccess.")

[erikhansen]

@erfanimani Ok, no problem.