Hello!

I've just installed Symfony 4 and would like to use it with the currently latest version of PHP-DI, the v6.

$ composer require php-di/php-di ^6.0
...
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - Installation request for php-di/php-di ^6.0 -> satisfiable by php-di/php-di[6.0.0].
    - Conclusion: remove nikic/php-parser v4.0.0
    - Conclusion: don't install nikic/php-parser v4.0.0

So the problem is, that one of the Symfony packages (namely symfony/maker-bundle) needs the nikic/php-parser ^4.0. And this dosn't meet the PHP-DI's requirements defined in its composer.json:

"require": {
    ...
    "nikic/php-parser": "^2.0|^3.0"
},

The nikic/PHP-Parser's v4 was released 18 days ago. And the PHP-DI's v6 was released about a week earlier. So is the restriction to the ^2.0|^3.0 just outdated and should be extended with ^4.0? If so, could the core developers please update it.

Thanks