Why such an error with Codeception?

Question

Codeception

I'm trying to install Codeception on a project with Yii2, that's actually what I did, I installed it globally like this

composer global require "codeception/codeception=2.1.*"
composer global require "codeception/specify=*"
composer global require "codeception/verify=*"

then I made this alias (I have ubuntu)

alias codecept="/home/user/.composer/vendor/bin/codecept"

codecept command outputs all commands I write
codecept bootstrap I get this error

In InitTemplate.php line 211:
Codeception is already installed in this directory

what have I not done before?