I can't install Doctrine Migrations via Composer - database

Question

I've searched everywhere to fix my problem but i think my problem is a new one and there is not solution.
I've added doctrine/migrations to my composer file, and when i type
composer update
this problem shows up:
Loading composer repositories with package information
Updating dependencies (including require-dev)
- Installing doctrine/migrations (dev-master a4f14d3)
Failed to download doctrine/migrations from source: Could not delete /var/www/vendor/doctrine/migrations/.git/objects/pack/tmp_idx_1vS7c6:
Now trying to download from dist
- Installing doctrine/migrations (dev-master a4f14d3)
[RuntimeException]
Could not delete /var/www/vendor/doctrine/migrations/.git/objects/pack/tmp_idx_1vS7c6:
My composer file:
{
"name": "symfony/framework-standard-edition",
"license": "MIT",
"type": "project",
"description": "The \"Symfony Standard Edition\" distribution",
"autoload": {
"psr-0": { "": "src/" }
},
"require": {
"php": ">=5.3.3",
"symfony/symfony": "2.3.*",
"doctrine/orm": "~2.2,>=2.2.3,<2.5",
"doctrine/dbal": "<2.5",
"doctrine/doctrine-bundle": "~1.2",
"doctrine/migrations": "dev-master",
"doctrine/doctrine-migrations-bundle": "dev-master",
"doctrine/doctrine-fixtures-bundle": "2.2.*",
"twig/extensions": "1.0.*",
"symfony/assetic-bundle": "~2.3",
"symfony/swiftmailer-bundle": "~2.3",
"symfony/monolog-bundle": "~2.4",
"sensio/distribution-bundle": "~2.3",
"sensio/framework-extra-bundle": "~3.0,>=3.0.2",
"sensio/generator-bundle": "~2.3",
"incenteev/composer-parameter-handler": "~2.0"
},
"scripts": {
"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"
]
},
"config": {
"bin-dir": "bin"
},
"minimum-stability" : "dev",
"prefer-stable" : true,
"extra": {
"symfony-app-dir": "app",
"symfony-web-dir": "web",
"incenteev-parameters": {
"file": "app/config/parameters.yml"
},
"branch-alias": {
"dev-master": "2.3-dev"
}
}
}
Any ideas what is wrong?
After chmoding the /var/www/vendor i get this:
Loading composer repositories with package information
Updating dependencies (including require-dev)
- Installing doctrine/migrations (dev-master a4f14d3)
Cloning a4f14d3a3d397104e557ec65d1a4e43bb86e4ddf
Failed to download doctrine/migrations from source: Could not delete /var/www/vendor/doctrine/migrations/.git/objects/pack/tmp_pack_V57bD0:
Now trying to download from dist
- Installing doctrine/migrations (dev-master a4f14d3)
[RuntimeException]
Could not delete /var/www/vendor/doctrine/migrations/.git/objects/pack/tmp_pack_V57bD0: