Error when running composer install command

Question

when I run

php composer.phar install

i have this error

Dependency resolution completed in 0.476 seconds

Your requirements could not be resolved to an installable set of packages

Problem 1 - Conclusion: don't install symfony/cache v4.2.3

• Conclusion: don't install symfony/cache v4.2.2
• Conclusion: don't install symfony/cache v4.2.1
• Conclusion: don't install symfony/cache v4.2.0
• Conclusion: don't install symfony/cache v4.1.11
• Conclusion: don't install symfony/cache v4.1.10
• Conclusion: don't install symfony/cache v4.1.9
• Conclusion: don't install symfony/cache v4.1.8
• Conclusion: don't install symfony/cache v4.1.7
• Conclusion: don't install symfony/cache v4.1.6
• Conclusion: don't install symfony/cache v4.1.5
• Conclusion: don't install symfony/cache v4.1.4
• Conclusion: don't install symfony/cache v4.1.3
• Conclusion: don't install symfony/cache v4.1.2
• Conclusion: don't install symfony/cache v4.1.1
• Conclusion: don't install symfony/cache v4.1.0
• Conclusion: don't install symfony/cache v4.0.15
• Conclusion: don't install symfony/cache v4.0.14
• Conclusion: don't install symfony/cache v4.0.13
• Conclusion: don't install symfony/cache v4.0.12
• Conclusion: don't install symfony/cache v4.0.11
• Conclusion: don't install symfony/cache v4.0.10
• Conclusion: don't install symfony/cache v4.0.9
• Conclusion: don't install symfony/cache v4.0.8
• Conclusion: don't install symfony/cache v4.0.7
• Conclusion: don't install symfony/cache v4.0.6
• Conclusion: don't install symfony/cache v4.0.5
• Conclusion: don't install symfony/cache v4.0.4
• Conclusion: don't install symfony/cache v4.0.3
• Conclusion: don't install symfony/cache v4.0.2
• Conclusion: don't install symfony/cache v4.0.1
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.0
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.1
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.10
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.11
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.12
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.13
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.14
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.15
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.16
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.17
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.18
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.19
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.2
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.20
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.21
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.22
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.3
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.4
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.5
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.6
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.7
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.8
• don't install symfony/cache v4.0.0|don't install symfony/symfony v3.4.9
• Installation request for symfony/cache ^4.0 -> satisfiable by symfony/cache[v4.0.0, v4.0.1, v4.0.10, v4.0.11, v4.0.12, v4.0.13, v4.0.14, v4.0.15, v4.0.2, v4.0.3, v4.0.4, v4.0.5, v4.0.6, v4.0.7, v4.0.8, v4.0.9, v4.1.0, v4.1.1, v4.1.10, v4.1.11, v4.1.2, v4.1.3, v4.1.4, v4.1.5, v4.1.6, v4.1.7, v4.1.8, v4.1.9, v4.2.0, v4.2.1, v4.2.2, v4.2.3].
• Installation request for symfony/symfony 3.4.* -> satisfiable by symfony/symfony[v3.4.0, v3.4.1, v3.4.10, v3.4.11, v3.4.12, v3.4.13, v3.4.14, v3.4.15, v3.4.16, v3.4.17, v3.4.18, v3.4.19, v3.4.2, v3.4.20, v3.4.21, v3.4.22, v3.4.3, v3.4.4, v3.4.5, v3.4.6, v3.4.7, v3.4.8, v3.4.9].

this is the require part in the composer.json

 {
    "php": ">=7.0",
    "alcaeus/mongo-php-adapter": "^1.1",
    "doctrine/doctrine-bundle": "^1.9",
    "doctrine/doctrine-fixtures-bundle": "3.0.2",
    "doctrine/mongodb-odm": "^1.1.7",
    "doctrine/mongodb-odm-bundle": "^3.4.0",
    "firebase/php-jwt": "^5.0",
    "friendsofsymfony/jsrouting-bundle": "^2.2",
    "friendsofsymfony/oauth-server-bundle": "dev-master",
    "friendsofsymfony/rest-bundle": "^2.3",
    "gedmo/doctrine-extensions": "^2.4",
    "guzzlehttp/guzzle": "^6.3",
    "incenteev/composer-parameter-handler": "^2.1",
    "jms/serializer-bundle": "~2.3",
    "league/omnipay": "^3.0",
    "nelmio/cors-bundle": "^1.5",
    "omnipay/stripe": "dev-patch-1",
    "phramz/doctrine-annotation-scanner": "^1.0",
    "ramsey/uuid": "^3.8",
    "sensio/distribution-bundle": "^5.0.19",
    "sensio/framework-extra-bundle": "^5.1",
    "symfony/assetic-bundle": "^2.8",
    "symfony/cache": "^4.0",
    "symfony/expression-language": "^4.0",
    "symfony/ldap": "^4.1",
    "symfony/monolog-bundle": "^3.1.0",
    "symfony/polyfill-apcu": "^1.0",
    "symfony/swiftmailer-bundle": "^3.2",
    "symfony/symfony": "3.4.*",
    "twig/twig": "^1.0||^2.0"
}

Any one can help me please ?

Answer 1

Your problem is that you have defined "symfony/symfony": "3.4.*" in your composer.json, but you are also requiring "symfony/cache": "^4.0". The issue with that is the 4.0 version is only compatible with symfony versions greater or equal 4.0.

So you should downgrade your symfony/cache version to 3.4 like this:

{
    ...
    "symfony/cache": "^3.4",
    "symfony/symfony": "3.4.*",
    ...
}