Laravel composer install failed

Question

I pulled my laravel installation from my remote server to my local machine and want now to execute 'composer install' to install all required packages. The whole thing worked in the past smoothly. But now I receive this error:

• laravel/framework v5.1.17 requires symfony/dom-crawler 2.7.* -> satisfiable by symfony/dom-crawler[2.7.x-dev, v2.7.0, v2.7.0-BETA1, v2.7.0-BETA2, v2.7.1, v2.7.10, v2.7.11, v2.7.12, v2.7.13, v2.7.14, v2.7.15, v2.7.16, v2.7.17, v2.7.18, v2.7.19, v2.7.2, v2.7.3, v2.7.4, v2.7.5, v2.7.6, v2.7.7, v2.7.8, v2.7.9] but these conflict with your requirements or minimum-stability.

My composer.json looks like this:

> {
>     "name": "laravel/laravel",
>     "description": "The Laravel Framework.",
>     "keywords": ["framework", "laravel"],
>     "license": "MIT",
>     "type": "project",
>     "require": {
>         "php": ">=5.5.9",
>         "laravel/framework": "5.2.*",
>         "league/fractal": "^0.12.0",
>         "pda/pheanstalk": "^3.1",
>         "witty/laravel-push-notification": "dev-master",
>         "illuminate/html": "^5.0",
>         "way/generators": "^3.0",
>         "laracasts/generators": "^1.1"
>     },
>     "require-dev": {
>         "fzaninotto/faker": "~1.4",
>         "mockery/mockery": "0.9.*",
>         "phpunit/phpunit": "~4.0",
>         "phpspec/phpspec": "~2.1",
>         "symfony/dom-crawler": "~3.0"
>     },
>     "autoload": {
>         "classmap": [
>             "database"
>         ],
>         "psr-4": {
>             "App\\": "app/"
>         }
>     },
>     "autoload-dev": {
>         "classmap": [
>             "tests/TestCase.php"
>         ]
>     },
>     "scripts": {
>         "post-install-cmd": [
>             "php artisan clear-compiled",
>             "php artisan optimize"
>         ],
>         "pre-update-cmd": [
>             "php artisan clear-compiled"
>         ],
>         "post-update-cmd": [
>             "php artisan optimize"
>         ],
>         "post-root-package-install": [
>             "php -r \"copy('.env.example', '.env');\""
>         ],
>         "post-create-project-cmd": [
>             "php artisan key:generate"
>         ]
>     },
>     "config": {
>         "preferred-install": "dist"
>     } }

I haven't changed a single bit of my code but just did a clean install of my computer.

When I try to change to dom-crawler ~2.7 I get this error:

>  Problem 1
>     - Conclusion: don't install laravel/framework v5.2.45
>     - Conclusion: don't install laravel/framework v5.2.44
>     - Conclusion: don't install laravel/framework v5.2.43
>     - Conclusion: don't install laravel/framework v5.2.42
>     - Conclusion: don't install laravel/framework 5.2.41
>     - Conclusion: don't install laravel/framework v5.2.40
>     - Conclusion: don't install laravel/framework v5.2.39
>     - Conclusion: don't install laravel/framework v5.2.38
>     - Conclusion: don't install laravel/framework v5.2.37
>     - Conclusion: don't install laravel/framework v5.2.36
>     - Conclusion: don't install laravel/framework v5.2.35
>     - Conclusion: don't install laravel/framework v5.2.34
>     - Conclusion: don't install laravel/framework v5.2.33
>     - Conclusion: don't install laravel/framework v5.2.32
>     - Conclusion: don't install laravel/framework v5.2.31
>     - Conclusion: don't install laravel/framework v5.2.30
>     - Conclusion: don't install laravel/framework v5.2.29
>     - Conclusion: don't install laravel/framework v5.2.28
>     - Conclusion: don't install laravel/framework v5.2.27
>     - Conclusion: don't install laravel/framework v5.2.26
>     - Conclusion: don't install laravel/framework v5.2.25
>     - Conclusion: don't install laravel/framework v5.2.24
>     - Conclusion: don't install laravel/framework v5.2.23
>     - Conclusion: don't install laravel/framework v5.2.22
>     - Conclusion: don't install laravel/framework v5.2.21
>     - Conclusion: don't install laravel/framework v5.2.20
>     - Conclusion: don't install laravel/framework v5.2.19
>     - Conclusion: don't install laravel/framework v5.2.18
>     - Conclusion: don't install laravel/framework v5.2.17
>     - Conclusion: don't install laravel/framework v5.2.16
>     - Conclusion: don't install laravel/framework v5.2.15
>     - Conclusion: don't install laravel/framework v5.2.14
>     - Conclusion: don't install laravel/framework v5.2.13
>     - Conclusion: don't install laravel/framework v5.2.12
>     - Conclusion: don't install laravel/framework v5.2.11
>     - Conclusion: don't install laravel/framework v5.2.10
>     - Conclusion: don't install laravel/framework v5.2.9
>     - Conclusion: don't install laravel/framework v5.2.8
>     - Conclusion: don't install laravel/framework v5.2.7
>     - Conclusion: don't install laravel/framework v5.2.6
>     - Conclusion: don't install laravel/framework v5.2.5
>     - Conclusion: don't install laravel/framework v5.2.4
>     - Conclusion: don't install laravel/framework v5.2.3
>     - Conclusion: don't install laravel/framework v5.2.2
>     - Conclusion: don't install laravel/framework v5.2.1
>     - witty/laravel-push-notification dev-master requires illuminate/support 5.0.* | 5.1.* -> satisfiable by
> laravel/framework[v5.1.17], illuminate/support[v5.0.0, v5.0.22,
> v5.0.25, v5.0.26, v5.0.28, v5.0.33, v5.0.4, v5.1.1, v5.1.13, v5.1.16,
> v5.1.2, v5.1.20, v5.1.22, v5.1.25, v5.1.28, v5.1.30, v5.1.31, v5.1.41,
> v5.1.6, v5.1.8].
>     - witty/laravel-push-notification dev-master requires illuminate/support 5.0.* | 5.1.* -> satisfiable by
> laravel/framework[v5.1.17], illuminate/support[v5.0.0, v5.0.22,
> v5.0.25, v5.0.26, v5.0.28, v5.0.33, v5.0.4, v5.1.1, v5.1.13, v5.1.16,
> v5.1.2, v5.1.20, v5.1.22, v5.1.25, v5.1.28, v5.1.30, v5.1.31, v5.1.41,
> v5.1.6, v5.1.8].
>     - Can only install one of: laravel/framework[v5.2.0, v5.1.17].
>     - don't install illuminate/support v5.0.0|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.0.22|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.0.25|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.0.26|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.0.28|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.0.33|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.0.4|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.1|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.13|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.16|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.2|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.20|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.22|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.25|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.28|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.30|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.31|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.41|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.6|don't install laravel/framework v5.2.0
>     - don't install illuminate/support v5.1.8|don't install laravel/framework v5.2.0
>     - Installation request for laravel/framework 5.2.* -> satisfiable by laravel/framework[5.2.41, v5.2.0, v5.2.1, v5.2.10, v5.2.11,
> v5.2.12, v5.2.13, v5.2.14, v5.2.15, v5.2.16, v5.2.17, v5.2.18,
> v5.2.19, v5.2.2, v5.2.20, v5.2.21, v5.2.22, v5.2.23, v5.2.24, v5.2.25,
> v5.2.26, v5.2.27, v5.2.28, v5.2.29, v5.2.3, v5.2.30, v5.2.31, v5.2.32,
> v5.2.33, v5.2.34, v5.2.35, v5.2.36, v5.2.37, v5.2.38, v5.2.39, v5.2.4,
> v5.2.40, v5.2.42, v5.2.43, v5.2.44, v5.2.45, v5.2.5, v5.2.6, v5.2.7,
> v5.2.8, v5.2.9].
>     - Installation request for witty/laravel-push-notification dev-master -> satisfiable by
> witty/laravel-push-notification[dev-master].

Answer 1

Library witty/laravel-push-notification is too old to install Laravel in version 5.2. One of dependencies of laravel-push-notification is illuminate/support in version "5.0.* | 5.1.*" .

You're trying to install Laravel 5.2 but that library needs Laravel 5.1 to works.

PS Also try to not remove composer.lock next time, sometimes it can save project.