Wouldn't it make more sense to show the full template of the autoconfigure? Autoconfigure works based on an interface(/class?), thus it would make sense to see what other configuration is being added by this.

Sorry, I don't understand. What is the the full template of the autoconfigure ? Do you propose to display like this:

    _instanceof:
        Symfony\Component\Security\Core\Authorization\Voter\VoterInterface:
            tags: [security.voter]

or do you propose to display like the output of the command php ./bin/console debug:container App\\Security\\PostVoter with the information of autoconfigure ?

Information for Service "App\Security\PostVoter"
================================================

 ---------------- ------------------------ 
  Option           Value                   
 ---------------- ------------------------ 
  Service ID       App\Security\PostVoter  
  Class            App\Security\PostVoter  
  Tags             security.voter          
  Public           no                      
  Synthetic        no                      
  Lazy             no                      
  Shared           yes                     
  Abstract         no                      
  Autowired        yes                     
  Autoconfigured   yes                     
  Autoconfigure class Symfony\Component\Security\Core\Authorization\Voter\VoterInterface
  Autoconfigure tag security.voter
 ---------------- ------------------------ 

What about something like this?

Autoconfiguration for "Symfony\Component\Security\Core\Authorization\Voter\VoterInterface"
================================================

 ---------------- ------------------------ 
  Option           Value                   
 ---------------- ------------------------ 
  Tags             security.voter
  Public           no
  Any other options and values etc.
 ---------------- ------------------------ 

The command would have been useful to me during a migration of a project to the autowiring/autoconfigure.

Every time, I wondered if I could delete the configuration or not in services.yaml to reduce its size.

The command allows to know the autonconfiguring tags.
Which interface/class should be implemented to have autoconfiguration applied ?

If there is a need to know the full template, the command debug:container App\\Security\\PostVoter can be used. I have not yet meet the need to have the full template of the autoconfigure.

I really think such a command is a nice addition.
@iltar's comment is relevant especially now that autoconfiguration works for function calls (see #26768).

Maybe a separate command could be worth it? debug:autoconfiguration
by default it could display as @iltar suggests, and when the --tags is passed, be grouped by tags?

rebase needed (needs to account for the new show-hidden option)

@nicolas-grekas I create the separate command in #28730

Closing in favor of #28730