Symfony version(s) affected: 4.0.9

Description

We use ENV variables for mapping file links in exception. After upgrade to 4.0.9 we get

 Environment variables "APP_IDE" are never used. Please, check your container's configuration.``` when running cache:clear although it is used in the framework config.

How to reproduce
.env file

APP_IDE=phpstorm://open?file=%f&line=%l&/var/www/html/>/home/path/to/project/

framework.yaml file

parameters:
    env(APP_IDE): ~

framework:
    ide: '%env(APP_IDE)%'
    ...

After running cache:clear the "never used" error message shown in console

Possible Solution

After some digging in the source i found the debug.file_link_format parameter and passing the ENV to this solves the problem, but I can't find any documentation about this.