Phpdocumentor: Can't install via composer

[Siemienik]

Hi, I have some problems when i tried installing phpDocumentor.
There it is:

Problem 1
    - phpdocumentor/phpdocumentor v2.3.1 requires dompdf/dompdf dev-master@dev -> satisfiable by dompdf/dompdf[dev-master] but these conflict with your requirements or minimum-stability.
    - phpdocumentor/phpdocumentor v2.3.0 requires dompdf/dompdf dev-master@dev -> satisfiable by dompdf/dompdf[dev-master] but these conflict with your requirements or minimum-stability.
    - Conclusion: don't install phpdocumentor/phpdocumentor v2.9.0
    - phpdocumentor/phpdocumentor v2.0.0 requires phpdocumentor/fileset 1.*@beta -> satisfiable by phpdocumentor/fileset[1.0.0].
    - phpdocumentor/phpdocumentor v2.0.1 requires phpdocumentor/fileset 1.*@beta -> satisfiable by phpdocumentor/fileset[1.0.0].
    - phpdocumentor/phpdocumentor v2.1.0 requires phpdocumentor/fileset ~1.0 -> satisfiable by phpdocumentor/fileset[1.0.0].
    - phpdocumentor/phpdocumentor v2.2.0 requires phpdocumentor/fileset ~1.0 -> satisfiable by phpdocumentor/fileset[1.0.0].
    - phpdocumentor/phpdocumentor v2.3.2 requires phpdocumentor/fileset ~1.0 -> satisfiable by phpdocumentor/fileset[1.0.0].
    - phpdocumentor/phpdocumentor v2.4.0 requires phpdocumentor/fileset ~1.0 -> satisfiable by phpdocumentor/fileset[1.0.0].
    - phpdocumentor/phpdocumentor v2.5.0 requires phpdocumentor/fileset ~1.0 -> satisfiable by phpdocumentor/fileset[1.0.0].
    - phpdocumentor/phpdocumentor v2.6.0 requires phpdocumentor/fileset ~1.0 -> satisfiable by phpdocumentor/fileset[1.0.0].
    - phpdocumentor/phpdocumentor v2.6.1 requires phpdocumentor/fileset ~1.0 -> satisfiable by phpdocumentor/fileset[1.0.0].
    - phpdocumentor/phpdocumentor v2.7.0 requires phpdocumentor/fileset ~1.0 -> satisfiable by phpdocumentor/fileset[1.0.0].
    - phpdocu``mentor/phpdocumentor v2.7.1 requires phpdocumentor/fileset ~1.0 -> satisfiable by phpdocumentor/fileset[1.0.0].
    - phpdocumentor/phpdocumentor v2.8.0 requires phpdocumentor/fileset ~1.0 -> satisfiable by phpdocumentor/fileset[1.0.0].
    - phpdocumentor/phpdocumentor v2.8.1 requires phpdocumentor/fileset ~1.0 -> satisfiable by phpdocumentor/fileset[1.0.0].
    - phpdocumentor/phpdocumentor v2.8.2 requires phpdocumentor/fileset ~1.0 -> satisfiable by phpdocumentor/fileset[1.0.0].
    - phpdocumentor/phpdocumentor v2.8.3 requires phpdocumentor/fileset ~1.0 -> satisfiable by phpdocumentor/fileset[1.0.0].
    - phpdocumentor/phpdocumentor v2.8.4 requires phpdocumentor/fileset ~1.0 -> satisfiable by phpdocumentor/fileset[1.0.0].
    - phpdocumentor/phpdocumentor v2.8.5 requires phpdocumentor/fileset ~1.0 -> satisfiable by phpdocumentor/fileset[1.0.0].
    - Conclusion: don't install phpdocumentor/fileset 1.0.0|install phpdocumentor/phpdocumentor v2.9.0
    - Installation request for phpdocumentor/phpdocumentor 2.* -> satisfiable by phpdocumentor/phpdocumentor[v2.0.0, v2.0.1, v2.1.0, v2.2.0, v2.3.0, v2.3.1, v2.3.2, v2.4.0, v2.5.0, v2.6.0, v2.6.1, v2.7.0, v2.7.1, v2.8.0, v2.8.1, v2.8.2, v2.8.3, v2.8.4, v2.8.5, v2.9.0].

My composer.json:
{ "require": { "php": ">=7.1.0" }, "minimum-stability": "stable", "require-dev": { "friendsofphp/php-cs-fixer": "^2.6", "phpunit/phpunit": "^6.4", "phpdocumentor/phpdocumentor": "2.*" }, }

Thank You about help

[demiankatz]

I believe the problem here is that php-cs-fixer and phpDocumentor currently have incompatible dependencies. I worked around this in my own project by installing phpDocumentor as a downloaded .phar rather than using Composer.

[jaapio]

We do not recommend the installation via composer. Please try our phar package. We are not able to support all configurations.