phpunit: PHPUnit won't install via Composer on PHP7.2

Q	A
PHPUnit version	7.0.2
PHP version	7.2.2-3+ubuntu16.04.1+deb.sury.org+1
Installation Method	Composer

vagrant@homestead:~/Code/project$ composer require --dev phpunit/phpunit ^7
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - Installation request for sebastian/diff (locked at 2.0.1) -> satisfiable by sebastian/diff[2.0.1].
    - phpunit/phpunit 7.0.0 requires sebastian/diff ^3.0 -> satisfiable by sebastian/diff[3.0.0].
    - phpunit/phpunit 7.0.1 requires sebastian/diff ^3.0 -> satisfiable by sebastian/diff[3.0.0].
    - phpunit/phpunit 7.0.2 requires sebastian/diff ^3.0 -> satisfiable by sebastian/diff[3.0.0].
    - Conclusion: don't install sebastian/diff 3.0.0
    - Installation request for phpunit/phpunit ^7 -> satisfiable by phpunit/phpunit[7.0.0, 7.0.1, 7.0.2].


Installation failed, reverting ./composer.json to its original content.
vagrant@homestead:~/Code/project$

About this issue

Original URL
State: closed
Created 6 years ago
Reactions: 6
Comments: 17 (2 by maintainers)

Most upvoted comments

Thanks @mvuajua! I got this error when trying to upgrade my phpunit by requiring it again. Solution for me was to uninstall phpunit and reinstall it:

$ composer remove phpunit/phpunit --dev
$ composer require phpunit/phpunit --dev

+157

connor11528 on May 25, 2018

What is the solution for this problem?

+32

ichbinbobby on May 16, 2018

If it can help someone:

If you want for example upgrade to phpunit ^9 without remove/require:

composer require --dev --update-with-dependencies phpunit/phpunit:^9

+17

lugus on Feb 19, 2020

You have sebastian/diff locked to a version that is not compatible with the version of PHPUnit you are trying to install. This is not a PHPUnit issue.

No response and nothing to add nethertheless… And he closed the thread 👎

+14

Andre-Sekou on Nov 28, 2018

I had the same problem, even though sebastian/diff was not locked down anywhere (and only required to be ^2 by phpunit itself according to composer why).

Only solution for me was to uninstall phpunit (triggering an uninstall of sebastian/diff as well) and then to reinstall phpunit.

ghost on May 21, 2018

I solved by running sudo apt-get update sudo apt install php-xml

ehsanbigzad on Apr 10, 2020

This update other related sebastian dependencies as well so this solution works $ composer remove phpunit/phpunit --dev $ composer require phpunit/phpunit --dev

versha000 on Jun 11, 2019

You have sebastian/diff locked to a version that is not compatible with the version of PHPUnit you are trying to install. This is not a PHPUnit issue.

sebastianbergmann on Mar 7, 2018