failed to compile php, deployment php app with composer dependencies

Trying to deploy my symfony app I have this error occured:

Counting objects: 74, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (36/36), done.
Writing objects: 100% (36/36), 14.54 KiB | 0 bytes/s, done.
Total 36 (delta 24), reused 0 (delta 0)
remote: Compressing source files... done.
remote: Building source:
remote: 
remote: -----> PHP app detected
remote: 
remote:  !     WARNING: Your 'composer.json' contains a non-'stable' setting
remote:        for 'minimum-stability'. This may cause the installation of
remote:        unstable versions of runtimes and extensions during this deploy.
remote:        It is recommended that you always use stability flags instead,
remote:        even if you have 'prefer-stable' enabled. For more information,
remote:        see https://getcomposer.org/doc/01-basic-usage.md#stability
remote: 
remote: -----> Bootstrapping...
remote: 
remote: gzip: stdin: not in gzip format
remote: tar: Child returned status 1
remote: tar: Error is not recoverable: exiting now
remote:  !     Push rejected, failed to compile PHP app.
remote: 
remote:  !     Push failed
remote: Verifying deploy...
remote: 
remote: !   Push rejected to my-app.
remote: 
To https://git.heroku.com/my-app.git
 ! [remote rejected] master -> master (pre-receive hook declined)
error: impossible de pousser des références vers 'https://git.heroku.com/my-app.git'

I really don't understand why, and I am not sure it is in relation with php buildpack. Before this error not appear and I have the same configuration as before.

This is my composer.json file:

{
    "name": "symfony/framework-standard-edition",
    "license": "MIT",
    "type": "project",
    "description": "The \"Symfony Standard Edition\" distribution",
    "autoload": {
        "psr-4": { "": "src/" }
    },
    "minimum-stability": "dev",
    "prefer-stable": true,
    "require": {
        "php": "~5.6.0",
        "ext-mbstring": "*",
        "ext-mcrypt": "*",
        "symfony/symfony": "2.7.*",
        "doctrine/orm": "^2.4.8",
        "doctrine/doctrine-bundle": "~1.4",
        "symfony/assetic-bundle": "~2.3",
        "symfony/swiftmailer-bundle": "~2.3",
        "symfony/monolog-bundle": "~2.8",
        "sensio/distribution-bundle": "~4.0",
        "sensio/framework-extra-bundle": "^3.0.2",
        "incenteev/composer-parameter-handler": "~2.0",
        "friendsofsymfony/user-bundle": "~2.0@dev",
        "knplabs/doctrine-behaviors": "~1.1",
        "friendsofsymfony/jsrouting-bundle": "^1.5",
        "jms/serializer-bundle": "^1.1",
        "genemu/form-bundle": "2.2.*",
        "elao/web-profiler-extra-bundle" : "~2.3",
        "a2lix/translation-form-bundle": "^2.0",
        "ircmaxell/password-compat": "~1.0",
        "vich/uploader-bundle": "^0.14.0",
        "liip/imagine-bundle": "^1.4",
        "doctrine/data-fixtures": "^1.1",
        "league/geotools": "@stable",
        "winzou/state-machine-bundle": "~0.2.2",
        "doctrine/doctrine-fixtures-bundle": "~2.2",
        "muka/shape-reader": "dev-master",
        "league/csv": "^8.0",
        "ronanguilloux/isocodes": "^2.0",
        "liuggio/excelbundle": "~2.0",
        "liip/doctrine-cache-bundle": "^1.0",
        "evheniy/robots-txt-bundle": "1.*",
        "php-amqplib/rabbitmq-bundle": "^1.9",
        "icicleio/icicle": "^0.9.6"
    },
    "require-dev": {
        "sensio/generator-bundle": "~2.3",
        "heroku/heroku-buildpack-php": "*"
    },
    "scripts": {
        "pre-install-cmd": [
            "BetonDirect\\EntityBundle\\HerokuDatabase::populateEnvironment"
        ],
        "post-install-cmd": [
            "Incenteev\\ParameterHandler\\ScriptHandler::buildParameters",
            "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::buildBootstrap",
            "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::clearCache",
            "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installAssets",
            "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installRequirementsFile",
            "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::prepareDeploymentTarget"
        ],
        "post-update-cmd": [
            "Incenteev\\ParameterHandler\\ScriptHandler::buildParameters",
            "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::buildBootstrap",
            "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::clearCache",
            "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installAssets",
            "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installRequirementsFile",
            "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::prepareDeploymentTarget"
        ],
        "compile": [
          "php app/console assetic:dump --no-debug"
        ]
    },
    "config": {
        "bin-dir": "bin"
    },
    "extra": {
        "symfony-app-dir": "app",
        "symfony-web-dir": "web",
        "symfony-assets-install": "hard-copy",
        "incenteev-parameters": {
            "file": "app/config/parameters.yml",
        },
        "branch-alias": {
            "dev-master": "2.7-dev"
        },
        "heroku": {
            "php-config": [
                "date.timezone=Europe/Paris"
            ]
        }
    }
}

For depolying I run this command: git push heroku my-branch:master and I see the hroku logs that build the app.

More explanation here: http://stackoverflow.com/questions/38523304/deploy-symfony-app-on-heroku-return-push-failed-error

Someone have the same problem ?

heroku / legacy-cli

failed to compile php, deployment php app with composer dependencies #1985