Error instalation

[Grafs]

composer global require pixline/wp-cli-php-devtools=0.2.5

Return

Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.

Problem 1
- pixline/wp-cli-php-devtools 0.2.5 requires phpmd/phpmd 1.5.* -> satisfiabl
e by phpmd/phpmd[1.5.0, 1.5.1, 1.5.x-dev] but these conflict with your requireme
nts or minimum-stability.
- pixline/wp-cli-php-devtools 0.2.5 requires pixline/php_codesniffer_wp_stan
dard dev-master -> satisfiable by pixline/php_codesniffer_wp_standard[dev-master
] but these conflict with your requirements or minimum-stability.
- Installation request for pixline/wp-cli-php-devtools 0.2.5 -> satisfiable
by pixline/wp-cli-php-devtools[0.2.5].

Installation failed, reverting ./composer.json to its original content.