Deprecate symfony solve
I found this one tricky to solve as well. It's not automatically resolved by a composer update because it's part of the configuration that's only applied from it's recipe when you require a package for the first time.
You'll have to change three things that are also changed in the default configuration for 4.4 (I used dots below to indicate nested keys):
- in
config/packages/twig.yamladdtwig.exception_controller: null - in
config/routes/dev/twig.yamlchange the_errors.resourceto@FrameworkBundle/Resources/config/routing/errors.xml - rename
config/routes/dev/twig.yamltoconfig/routes/dev/framework.yaml