2.5 -> 2.6 dropped symfony/console v2. Breaks symfony 2.8 install/update on PHP 7.3

[uvimoran]

Bug Report

Q	A
BC Break	yes
Version	any 2.6

Summary

doctrine/orm v2.6 breaks the installation of symfony 2.8 projects on PHP 7.3 (or updating existing ones) due to the removal of "symfony/console": "~2.5" in composer.json

This restriction results in doctrine/orm being stuck at v2.5.14 in symfony 2.8 projects, which until php 7.2 worked fine, but fails with this error if composer update is executed under PHP 7.3:

Script Sensio\Bundle\DistributionBundle\Composer\ScriptHandler::clearCache handling the symfony-scripts event terminated with an exception
                                                                              
  [RuntimeException]                                                           
  An error occurred when executing the "'cache:clear --no-warmup'" command:    
                                                                       
    [Symfony\Component\Debug\Exception\ContextErrorException]          
                                                                       
    Warning: "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"?

Which is caused by doctrine/orm v2.5 PHP 7.3 compatibility issues mentioned here.

Current behavior

Symfony 2.8 projects cannot be installed or updated on PHP 7.3 as they are stuck with an incompatible version of doctrine/orm due to composer dependency restrictions.

How to reproduce

1. Create a symfony 2.8 project on a PHP 7.3 machine:
   php composer.phar create-project symfony/framework-standard-edition my_project_name "2.8.*"
2. Process fails due to installed symfony/orm v2.5.14 being incompatible with PHP 7.3

Expected behavior

If it is possible for symfony 2.8 projects to get doctrine/orm updated to v2.6 without compatibility issues, fixing this would allow symfony 2.8 projects to be installed or updated in PHP 7.3 environments.

[SenseException]

Symfony 2.8 is on "Security fixes only" and will be dropped end of this year. It also wasn't updated for PHP 7.3. I isn't reasonable for Doctrine to depend on an old and unsupported console version.

I suggest to update your Symfony project to one of the recent versions.