ExceptionSubscriberInterface::onTransportException() now accepts ResponseInterface|null
for its response parameter. The response is null when the HTTP client throws before
returning a response object.
Update all implementations to accept ResponseInterface|null and handle null before
accessing the response. Implementations that still require ResponseInterface are
incompatible with the updated interface.
The signature of onHttpException() is unchanged and its response is always available.
The Doctrine queue now requires a nullable redirected_to text column to store the final redirect destination.
Update existing queue tables before crawling with 2.0. Call DoctrineQueue::createSchema() to migrate the
queue table, or include DoctrineQueue::getTableSchema() in your application's schema management.
Custom queue implementations must also persist and restore CrawlUri::getRedirectedTo() when storing
or loading a crawl URI, including updates to already processed entries.