Magenta 2 snippets: Custom debug log file

debug_log.xml

<virtualType name="VirtualDebug" type="Magento\Framework\Logger\Handler\Base">
    <arguments>
        <argument name="fileName" xsi:type="string">/var/log/custom_error.log</argument>
    </arguments>
</virtualType>
<virtualType name="VirtualLogger" type="Magento\Framework\Logger\Monolog">
    <arguments>
        <argument name="handlers" xsi:type="array">
            <item name="debug" xsi:type="object">VirtualDebug</item>
        </argument>
    </arguments>
</virtualType>
<type name="Vendor\Model\Model\Log">
    <arguments>
        <argument name="logger" xsi:type="object">VirtualLogger</argument>
    </arguments>
</type>