Composer errir message

installing with
composer create-project slim/slim-skeleton web
I got this message
composer msg : Package phpunit/phpunit-mock-objects is abandoned, you should avoid using it. No replacement was suggested.
Is there anything I have to take care of ?

There is nothing you need to take care of there. The current version of Slim uses phpunit version 4/5, while the new version of Slim (not yet released) will use phpunit version 7.

ok thanks
Is there anyway to tell composer to use he current version with ā€˜skeleton’ and not the new one

I’m not sure what mean by ā€œthe new oneā€. Composer will install the version of phpunit that the package was designed for.

I refer to your phrase :

while the new version of Slim (not yet released) will use phpunit version 7.

when I do composer create-project slim/slim-skeleton web
I want to use the last stable version not the new one not (yet released)

That command will get you the latest stable version of slim/slim-skeleton that meets the requirements of your environment.

Depending on your environment, if you:
$ composer create-project slim/slim-skeleton web

You will be getting slim/slim-skeleton (3.1.6), which requires slim/slim": "^3.1, which has a dev requirement of "phpunit/phpunit": "^4.0".