Class 'Psr\Log\LogLevel' not found in ErrorHandler.php

Question

using composer update or composer install getting this error:

Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Nothing to install or update
Generating autoload files
> Incenteev\ParameterHandler\ScriptHandler::buildParameters
Updating the "app/config/parameters.yml" file
> Sensio\Bundle\DistributionBundle\Composer\ScriptHandler::buildBootstrap
> Sensio\Bundle\DistributionBundle\Composer\ScriptHandler::clearCache
PHP Fatal error:  Class 'Psr\Log\LogLevel' not found in /var/www/html/Project/MRA/vendor/symfony/symfony/src/Symfony/Component/Debug/ErrorHandler.php on line 121
Script Sensio\Bundle\DistributionBundle\Composer\ScriptHandler::clearCache handling the post-install-cmd event terminated with an exception



  [RuntimeException]                                                                                                                                             
  An error occurred when executing the "'cache:clear --no-warmup'" command:                                                                                      
  PHP Fatal error:  Class 'Psr\Log\LogLevel' not found in /var/www/html/Project/MRA/vendor/symfony/symfony/src/Symfony/Component/Debug/ErrorHandler.php on line  
   121                                                                                                                                                           
  .                                                                                                                                                              



install [--prefer-source] [--prefer-dist] [--dry-run] [--dev] [--no-dev] [--no-plugins] [--no-custom-installers] [--no-autoloader] [--no-scripts] [--no-progress] [-v|vv|vvv|--verbose] [-o|--optimize-autoloader] [-a|--classmap-authoritative] [--ignore-platform-reqs] [--] [<packages>]...

I'm using symfony 2.7.7 and here is my composer.json:

• "php": ">=5.3.9",
• "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": "~2.4",
• "sensio/distribution-bundle": "~4.0",
• "sensio/framework-extra-bundle": "^3.0.2",
• "incenteev/composer-parameter-handler": "~2.0",
• "friendsofsymfony/user-bundle": "~1.3",
• "mopa/bootstrap-bundle": "dev-master",
• "twbs/bootstrap": "^3.3",
• "knplabs/knp-paginator-bundle": "dev-master",
• "knplabs/knp-menu-bundle": "2.0.*@dev",
• "knplabs/knp-menu": "2.0.*@dev",
• "craue/formflow-bundle": "~2.0",
• "friendsofsymfony/rest-bundle": "^1.7",
• "sonata-project/admin-bundle": "2.3.*",
• "sonata-project/doctrine-orm-admin-bundle": "2.3.*",
• "sonata-project/user-bundle": "dev-master",
• "sonata-project/datagrid-bundle": "dev-master",
• "siphoc/pdf-bundle": "1.2.*",
• "knplabs/knp-snappy-bundle": "^1.3",
• "sonata-project/easy-extends-bundle": "^2.1"

Answer 1

Ok, PSR Logger wasn't in the composer.json, so I added "psr/log": "dev-master" into composer.json and fixed the error. PS: don't know why suddenly it didn't work just because it wasn't installed!