Problem 1

[olariuromeo]

composer require "drupal/devel:1.x-dev" get this error
Your requirements could not be resolved to an installable set of packages.

Problem 1
- drupal/devel dev-1.x requires symfony/var-dumper ~2.7|^3 -> found symfony/var-dumper[v2.7.0-BETA1, ..., 2.8.x-dev, v3.0.0-BETA1, ..., 3.4.x-dev] but these were not loaded, likely because it conflicts with another require.
- drupal/devel 1.x-dev is an alias of drupal/devel dev-1.x and thus requires it to be installed too.
- Root composer.json requires drupal/devel 1.x-dev -> satisfiable by drupal/devel[1.x-dev (alias of dev-1.x)].

Installation failed, reverting ./composer.json and ./composer.lock to their original content.

[Ni3tzsch]

i also have this issue