Symfony version(s) affected

5.4 & others

Description

Some production setups set disable_functions to include var_dump (and exec, shell_exec, phpinfo, etc) for security purposes. This means that var_dump() may not be always be callable. This becomes relevant here:

The most common case is that on_progress is not set, so is_callable('var_dump') is the most common pattern.

This is a problem from PHP 8.0+ because the behaviour changed for is_callable('var_dump') when the function is disabled.

How to reproduce

$ # PHP 7.4
$ php -d'disable_functions=var_dump' -r 'var_export(is_callable("var_dump"));'
true

$ # PHP 8.0
$ php -d'disable_functions=var_dump' -r 'var_export(is_callable("var_dump"));'
false

Possible Solution

Perhaps switch var_dump to something innocuous like is_int?

Additional Context

No response