Composer: Cannot install behat and mink in laravel 5.2 new project

Question

I want to learn BDD using behat in a laravel project but I come accross dependencies problems with composer (this may be a very basic question but I have very little experience in composer so that I don't know what to do).

I create a new project

composer create-project laravel/laravel learning-behat

Then I want to get behat, mink and the mink-extension:

composer require behat/behat behat/mink behat/mink-extension --dev

But it fails and I get this output:

Using version ^3.0 for behat/behat
Using version ^1.7 for behat/mink
Using version ^2.1 for behat/mink-extension
./composer.json has been updated
> php artisan clear-compiled
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 behat/mink ^1.7 -> satisfiable by behat/mink[v1.7.0].
    - Conclusion: remove symfony/css-selector v3.0.1
    - Conclusion: don't install symfony/css-selector v3.0.1
    - behat/mink v1.7.0 requires symfony/css-selector ~2.1 -> satisfiable by symfony/css-selector[v2.8.0, v2.8.1].
    - Can only install one of: symfony/css-selector[v2.8.0, v3.0.1].
    - Can only install one of: symfony/css-selector[v2.8.1, v3.0.1].
    - Installation request for symfony/css-selector == 3.0.1.0 -> satisfiable by symfony/css-selector[v3.0.1].


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

When I only try to install behat ( composer require behat/behat --dev ), I also get errors:

Using version ^3.0 for behat/behat
./composer.json has been updated
> php artisan clear-compiled
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
    - Conclusion: don't install behat/behat v3.0.15
    - Conclusion: don't install behat/behat v3.0.14
    - Conclusion: don't install behat/behat v3.0.13
    - Conclusion: don't install behat/behat v3.0.12
    - Conclusion: don't install behat/behat v3.0.11
    - Conclusion: don't install behat/behat v3.0.10
    - Conclusion: don't install behat/behat v3.0.9
    - Conclusion: don't install behat/behat v3.0.8
    - Conclusion: don't install behat/behat v3.0.7
    - Conclusion: don't install behat/behat v3.0.6
    - Conclusion: don't install behat/behat v3.0.5
    - Conclusion: don't install behat/behat v3.0.4
    - Conclusion: don't install behat/behat v3.0.3
    - Conclusion: don't install behat/behat v3.0.2
    - Conclusion: don't install behat/behat v3.0.1
    - Conclusion: remove symfony/translation v3.0.1
    - Installation request for behat/behat ^3.0 -> satisfiable by behat/behat[v3.0.0, v3.0.1, v3.0.10, v3.0.11, v3.0.12, v3.0.13, v3.0.14, v3.0.15, v3.0.2, v3.0.3, v3.0.4, v3.0.5, v3.0.6, v3.0.7, v3.0.8, v3.0.9].
    - Conclusion: don't install symfony/translation v3.0.1
    - behat/behat v3.0.0 requires symfony/translation ~2.1 -> satisfiable by symfony/translation[v2.1.0, v2.1.1, v2.1.10, v2.1.11, v2.1.12, v2.1.13, v2.1.2, v2.1.3, v2.1.4, v2.1.5, v2.1.6, v2.1.7, v2.1.8, v2.1.9, v2.2.0, v2.2.1, v2.2.10, v2.2.11, v2.2.2, v2.2.3, v2.2.4, v2.2.5, v2.2.6, v2.2.7, v2.2.8, v2.2.9, v2.3.0, v2.3.1, v2.3.10, v2.3.11, v2.3.12, v2.3.13, v2.3.14, v2.3.15, v2.3.16, v2.3.17, v2.3.18, v2.3.19, v2.3.2, v2.3.20, v2.3.21, v2.3.22, v2.3.23, v2.3.24, v2.3.25, v2.3.26, v2.3.27, v2.3.28, v2.3.29, v2.3.3, v2.3.30, v2.3.31, v2.3.32, v2.3.33, v2.3.34, v2.3.35, v2.3.36, v2.3.4, v2.3.5, v2.3.6, v2.3.7, v2.3.8, v2.3.9, v2.4.0, v2.4.1, v2.4.10, v2.4.2, v2.4.3, v2.4.4, v2.4.5, v2.4.6, v2.4.7, v2.4.8, v2.4.9, v2.5.0, v2.5.1, v2.5.10, v2.5.11, v2.5.12, v2.5.2, v2.5.3, v2.5.4, v2.5.5, v2.5.6, v2.5.7, v2.5.8, v2.5.9, v2.6.0, v2.6.1, v2.6.10, v2.6.11, v2.6.12, v2.6.2, v2.6.3, v2.6.4, v2.6.5, v2.6.6, v2.6.7, v2.6.8, v2.6.9, v2.7.0, v2.7.1, v2.7.2, v2.7.3, v2.7.4, v2.7.5, v2.7.6, v2.7.7, v2.7.8, v2.8.0, v2.8.1].
    - Can only install one of: symfony/translation[v2.6.0, v3.0.1].
    - Can only install one of: symfony/translation[v2.6.1, v3.0.1].
    - Can only install one of: symfony/translation[v2.6.10, v3.0.1].
    - Can only install one of: symfony/translation[v2.6.11, v3.0.1].
    - Can only install one of: symfony/translation[v2.6.12, v3.0.1].
    - Can only install one of: symfony/translation[v2.6.2, v3.0.1].
    - Can only install one of: symfony/translation[v2.6.3, v3.0.1].
    - Can only install one of: symfony/translation[v2.6.4, v3.0.1].
    - Can only install one of: symfony/translation[v2.6.5, v3.0.1].
    - Can only install one of: symfony/translation[v2.6.6, v3.0.1].
    - Can only install one of: symfony/translation[v2.6.7, v3.0.1].
    - Can only install one of: symfony/translation[v2.6.8, v3.0.1].
    - Can only install one of: symfony/translation[v2.6.9, v3.0.1].
    - Can only install one of: symfony/translation[v2.7.0, v3.0.1].
    - Can only install one of: symfony/translation[v2.7.1, v3.0.1].
    - Can only install one of: symfony/translation[v2.7.2, v3.0.1].
    - Can only install one of: symfony/translation[v2.7.3, v3.0.1].
    - Can only install one of: symfony/translation[v2.7.4, v3.0.1].
    - Can only install one of: symfony/translation[v2.7.5, v3.0.1].
    - Can only install one of: symfony/translation[v2.7.6, v3.0.1].
    - Can only install one of: symfony/translation[v2.7.7, v3.0.1].
    - Can only install one of: symfony/translation[v2.7.8, v3.0.1].
    - Can only install one of: symfony/translation[v2.8.0, v3.0.1].
    - Can only install one of: symfony/translation[v2.8.1, v3.0.1].
    - Can only install one of: symfony/translation[v2.1.0, v3.0.1].
    - Can only install one of: symfony/translation[v2.1.1, v3.0.1].
    - Can only install one of: symfony/translation[v2.1.10, v3.0.1].
    - Can only install one of: symfony/translation[v2.1.11, v3.0.1].
    - Can only install one of: symfony/translation[v2.1.12, v3.0.1].
    - Can only install one of: symfony/translation[v2.1.13, v3.0.1].
    - Can only install one of: symfony/translation[v2.1.2, v3.0.1].
    - Can only install one of: symfony/translation[v2.1.3, v3.0.1].
    - Can only install one of: symfony/translation[v2.1.4, v3.0.1].
    - Can only install one of: symfony/translation[v2.1.5, v3.0.1].
    - Can only install one of: symfony/translation[v2.1.6, v3.0.1].
    - Can only install one of: symfony/translation[v2.1.7, v3.0.1].
    - Can only install one of: symfony/translation[v2.1.8, v3.0.1].
    - Can only install one of: symfony/translation[v2.1.9, v3.0.1].
    - Can only install one of: symfony/translation[v2.2.0, v3.0.1].
    - Can only install one of: symfony/translation[v2.2.1, v3.0.1].
    - Can only install one of: symfony/translation[v2.2.10, v3.0.1].
    - Can only install one of: symfony/translation[v2.2.11, v3.0.1].
    - Can only install one of: symfony/translation[v2.2.2, v3.0.1].
    - Can only install one of: symfony/translation[v2.2.3, v3.0.1].
    - Can only install one of: symfony/translation[v2.2.4, v3.0.1].
    - Can only install one of: symfony/translation[v2.2.5, v3.0.1].
    - Can only install one of: symfony/translation[v2.2.6, v3.0.1].
    - Can only install one of: symfony/translation[v2.2.7, v3.0.1].
    - Can only install one of: symfony/translation[v2.2.8, v3.0.1].
    - Can only install one of: symfony/translation[v2.2.9, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.0, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.1, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.10, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.11, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.12, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.13, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.14, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.15, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.16, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.17, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.18, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.19, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.2, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.20, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.21, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.22, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.23, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.24, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.25, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.26, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.27, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.28, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.29, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.3, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.30, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.31, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.32, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.33, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.34, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.35, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.36, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.4, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.5, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.6, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.7, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.8, v3.0.1].
    - Can only install one of: symfony/translation[v2.3.9, v3.0.1].
    - Can only install one of: symfony/translation[v2.4.0, v3.0.1].
    - Can only install one of: symfony/translation[v2.4.1, v3.0.1].
    - Can only install one of: symfony/translation[v2.4.10, v3.0.1].
    - Can only install one of: symfony/translation[v2.4.2, v3.0.1].
    - Can only install one of: symfony/translation[v2.4.3, v3.0.1].
    - Can only install one of: symfony/translation[v2.4.4, v3.0.1].
    - Can only install one of: symfony/translation[v2.4.5, v3.0.1].
    - Can only install one of: symfony/translation[v2.4.6, v3.0.1].
    - Can only install one of: symfony/translation[v2.4.7, v3.0.1].
    - Can only install one of: symfony/translation[v2.4.8, v3.0.1].
    - Can only install one of: symfony/translation[v2.4.9, v3.0.1].
    - Can only install one of: symfony/translation[v2.5.0, v3.0.1].
    - Can only install one of: symfony/translation[v2.5.1, v3.0.1].
    - Can only install one of: symfony/translation[v2.5.10, v3.0.1].
    - Can only install one of: symfony/translation[v2.5.11, v3.0.1].
    - Can only install one of: symfony/translation[v2.5.12, v3.0.1].
    - Can only install one of: symfony/translation[v2.5.2, v3.0.1].
    - Can only install one of: symfony/translation[v2.5.3, v3.0.1].
    - Can only install one of: symfony/translation[v2.5.4, v3.0.1].
    - Can only install one of: symfony/translation[v2.5.5, v3.0.1].
    - Can only install one of: symfony/translation[v2.5.6, v3.0.1].
    - Can only install one of: symfony/translation[v2.5.7, v3.0.1].
    - Can only install one of: symfony/translation[v2.5.8, v3.0.1].
    - Can only install one of: symfony/translation[v2.5.9, v3.0.1].
    - Installation request for symfony/translation == 3.0.1.0 -> satisfiable by symfony/translation[v3.0.1].


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

Answer 1

I found a working solution thanks to this answer on Stackoverflow.

Installing the dev-master version of behat, mink and mink-extension worked for me. So, instead of

composer require behat/behat behat/mink behat/mink-extension --dev

you need to do:

composer require behat/behat:dev-master behat/mink:dev-master behat/mink-extension:dev-master --dev