title: Symfony 4 do not build in Production: Attempted to load class "WebProfilerBundle" from namespace
body: <p>Symfony 4 do build in Dev mode but do not in Production mode while producing the error: </p>
  
  <p>Attempted to load class "WebProfilerBundle" from namespace.</p>
  
  <p>The WebProfilerBundle sure, is installed but should only used in Dev environment and should not used on Production builds.</p>
  
  <p>I am on Fedora30, no containerization involved.</p>
  
  <ul>
  <li>php -v => PHP 7.3.8 (cli) (built: Jul 30 2019 09:26:16) ( NTS )</li>
  <li>npm -v => 6.9.0</li>
  <li>yarn -v => 1.17.3</li>
  <li>composer.phar -V => Composer version 1.9.0 2019-08-02 20:55:32</li>
  <li>symfony -V => Symfony CLI version v4.6.4 (Tue Aug 13 16:14:53 CEST 2019)</li>
  <li>flex</li>
  </ul>
  
  <p>Active file versioning let me guess Production build chain is used (not present Dev builds):</p>
  
  <pre><code>$ ls -l public/build
  168 -rw-rw-r-- 1 rob rob 169693 31. Aug 15:39 0.376e4878.js
  184 -rw-rw-r-- 1 rob rob 185359 31. Aug 15:39 0.6ea45216.css
    4 -rw-rw-r-- 1 rob rob    404 31. Aug 15:39 app.00b96fcb.js
    4 -rw-rw-r-- 1 rob rob    213 31. Aug 15:39 app.f7e93431.css
    4 -rw-rw-r-- 1 rob rob    261 31. Aug 15:39 entrypoints.json
    4 drwxrwxr-x 2 rob rob   4096 31. Aug 15:39 fonts
    4 drwxrwxr-x 2 rob rob   4096 31. Aug 15:39 images
    4 -rw-rw-r-- 1 rob rob   1246 31. Aug 15:39 manifest.json
    4 -rw-rw-r-- 1 rob rob   1505 31. Aug 15:39 runtime.3c075ebb.js
  </code></pre>
  
  <p>bundles.php</p>
  
  <pre><code>&lt;?php
  
  return [
      Symfony\Bundle\FrameworkBundle\FrameworkBundle::class =&gt; ['all' =&gt; true],
      Sensio\Bundle\FrameworkExtraBundle\SensioFrameworkExtraBundle::class =&gt; ['all' =&gt; true],
      Doctrine\Bundle\DoctrineCacheBundle\DoctrineCacheBundle::class =&gt; ['all' =&gt; true],
      Doctrine\Bundle\DoctrineBundle\DoctrineBundle::class =&gt; ['all' =&gt; true],
      Doctrine\Bundle\MigrationsBundle\DoctrineMigrationsBundle::class =&gt; ['all' =&gt; true],
      Symfony\Bundle\SecurityBundle\SecurityBundle::class =&gt; ['all' =&gt; true],
      Symfony\Bundle\SwiftmailerBundle\SwiftmailerBundle::class =&gt; ['all' =&gt; true],
      Symfony\Bundle\TwigBundle\TwigBundle::class =&gt; ['all' =&gt; true],
  
      Symfony\Bundle\WebProfilerBundle\WebProfilerBundle::class =&gt; ['dev' =&gt; true, 'test' =&gt; true],
      Symfony\Bundle\DebugBundle\DebugBundle::class =&gt; ['dev' =&gt; true, 'test' =&gt; true],
      Symfony\Bundle\MakerBundle\MakerBundle::class =&gt; ['dev' =&gt; true],
  
      Symfony\Bundle\MonologBundle\MonologBundle::class =&gt; ['all' =&gt; true],
      Symfony\Bundle\WebServerBundle\WebServerBundle::class =&gt; ['dev' =&gt; true],
      Symfony\WebpackEncoreBundle\WebpackEncoreBundle::class =&gt; ['all' =&gt; true],
  ];
  </code></pre>
  
  <p>composer.json</p>
  
  <pre><code>{
      "type": "project",
      "license": "proprietary",
      "require": {
          "php": "^7.1.3",
          "ext-ctype": "*",
          "ext-iconv": "*",
          "sensio/framework-extra-bundle": "^5.4",
          "symfony/apache-pack": "^1.0",
          "symfony/asset": "4.3.*",
          "symfony/console": "4.3.*",
          "symfony/dotenv": "4.3.*",
          "symfony/expression-language": "4.3.*",
          "symfony/flex": "^1.4",
          "symfony/form": "4.3.*",
          "symfony/framework-bundle": "4.3.*",
          "symfony/http-client": "4.3.*",
          "symfony/intl": "4.3.*",
          "symfony/monolog-bundle": "^3.4",
          "symfony/orm-pack": "*",
          "symfony/process": "4.3.*",
          "symfony/security-bundle": "4.3.*",
          "symfony/serializer-pack": "*",
          "symfony/swiftmailer-bundle": "^3.1",
          "symfony/translation": "4.3.*",
          "symfony/twig-bundle": "4.3.*",
          "symfony/validator": "4.3.*",
          "symfony/web-link": "4.3.*",
          "symfony/webpack-encore-bundle": "^1.6",
          "symfony/yaml": "4.3.*"
      },
      "require-dev": {
          "symfony/debug-pack": "*",
          "symfony/maker-bundle": "^1.0",
          "symfony/profiler-pack": "*",
          "symfony/test-pack": "*",
          "symfony/web-server-bundle": "4.3.*"
      },
      "config": {
          "preferred-install": {
              "*": "dist"
          },
          "sort-packages": true
      },
      "autoload": {
          "psr-4": {
              "App\\": "src/"
          }
      },
      "autoload-dev": {
          "psr-4": {
              "App\\Tests\\": "tests/"
          }
      },
      "replace": {
          "paragonie/random_compat": "2.*",
          "symfony/polyfill-ctype": "*",
          "symfony/polyfill-iconv": "*",
          "symfony/polyfill-php71": "*",
          "symfony/polyfill-php70": "*",
          "symfony/polyfill-php56": "*"
      },
      "scripts": {
          "auto-scripts": {
              "cache:clear": "symfony-cmd",
              "assets:install %PUBLIC_DIR%": "symfony-cmd"
          },
          "post-install-cmd": [
              "@auto-scripts"
          ],
          "post-update-cmd": [
              "@auto-scripts"
          ]
      },
      "conflict": {
          "symfony/symfony": "*"
      },
      "extra": {
          "symfony": {
              "allow-contrib": false,
              "require": "4.3.*"
          }
      }
  }
  
  </code></pre>
  
  <p><strong>Production builds</strong> are build with:</p>
  
  <ul>
  <li>do $ <code>cp .env.local.prod .env.local</code> this contains..
  
  <ul>
  <li>the same as .env </li>
  <li>except this line <code>APP_ENV=prod</code></li>
  <li>except the missing APP_SECRET line</li>
  </ul></li>
  <li>do $ <code>rm -rf var/cache; rm -rf vendor</code></li>
  <li>do $ <code>../composer.phar install --no-dev --prefer-dist --optimize-autoloader --no-interaction</code></li>
  <li>do $ <code>yarn build</code></li>
  <li>do $ <code>rm .env.local</code> on finish the build</li>
  </ul>
  
  <p>But this seems not work, it produces the error from above. </p>
  
  <p><strong>Dev builds</strong> are done with:</p>
  
  <ul>
  <li>do $ <code>rm .env.local just use .env with APP_SECRET and APP_ENV=dev</code></li>
  <li>do $ <code>rm -rf var/cache; rm -rf vendor</code></li>
  <li>do $ <code>../composer.phar install</code></li>
  <li>do $ <code>yarn encore dev</code></li>
  </ul>
  
  <p>Error output from website </p>
  
  <pre><code>Attempted to load class "WebProfilerBundle" from namespace "Symfony\Bundle\WebProfilerBundle". Did you forget a "use" statement for another namespace?
  (1/1) ClassNotFoundException
  Attempted to load class "WebProfilerBundle" from namespace "Symfony\Bundle\WebProfilerBundle".
  Did you forget a "use" statement for another namespace?
  
  in Kernel.php line 23
  at Kernel-&gt;registerBundles()
  in Kernel.php line 424
  at Kernel-&gt;initializeBundles()
  in Kernel.php line 130
  at Kernel-&gt;boot()
  in Kernel.php line 193
  at Kernel-&gt;handle(object(Request))
  in index.php line 25
  </code></pre>
  
  <p>Build process</p>
  
  <pre><code>Loading composer repositories with package information
  Installing dependencies from lock file
  Package operations: 92 installs, 0 updates, 0 removals
    - Installing ocramius/package-versions (1.5.1): Loading from cache
    - Installing symfony/flex (v1.4.5): Loading from cache
    - Installing doctrine/lexer (1.1.0): Loading from cache
    - Installing doctrine/annotations (v1.7.0): Loading from cache
    - Installing doctrine/reflection (v1.0.0): Loading from cache
    - Installing doctrine/event-manager (v1.0.0): Loading from cache
    - Installing doctrine/collections (v1.6.2): Loading from cache
    - Installing doctrine/cache (v1.8.0): Loading from cache
    - Installing doctrine/persistence (1.1.1): Loading from cache
    - Installing doctrine/inflector (v1.3.0): Loading from cache
    - Installing doctrine/common (v2.10.0): Loading from cache
    - Installing psr/container (1.0.0): Loading from cache
    - Installing symfony/service-contracts (v1.1.5): Loading from cache
    - Installing symfony/polyfill-mbstring (v1.12.0): Loading from cache
    - Installing symfony/doctrine-bridge (v4.3.3): Loading from cache
    - Installing doctrine/doctrine-cache-bundle (1.3.5): Loading from cache
    - Installing doctrine/instantiator (1.2.0): Loading from cache
    - Installing symfony/stopwatch (v4.3.3): Loading from cache
    - Installing symfony/polyfill-php73 (v1.12.0): Loading from cache
    - Installing symfony/console (v4.3.3): Loading from cache
    - Installing zendframework/zend-eventmanager (3.2.1): Loading from cache
    - Installing zendframework/zend-code (3.3.1): Loading from cache
    - Installing ocramius/proxy-manager (2.2.3): Loading from cache
    - Installing doctrine/dbal (v2.9.2): Loading from cache
    - Installing doctrine/migrations (2.1.1): Loading from cache
    - Installing egulias/email-validator (2.1.11): Loading from cache
    - Installing jdorn/sql-formatter (v1.2.17): Loading from cache
    - Installing phpdocumentor/reflection-common (1.0.1): Loading from cache
    - Installing phpdocumentor/type-resolver (0.4.0): Loading from cache
    - Installing symfony/polyfill-php72 (v1.12.0): Loading from cache
    - Installing symfony/polyfill-intl-idn (v1.12.0): Loading from cache
    - Installing symfony/mime (v4.3.3): Loading from cache
    - Installing symfony/http-foundation (v4.3.3): Loading from cache
    - Installing symfony/event-dispatcher-contracts (v1.1.5): Loading from cache
    - Installing symfony/event-dispatcher (v4.3.3): Loading from cache
    - Installing psr/log (1.1.0): Loading from cache
    - Installing symfony/debug (v4.3.3): Loading from cache
    - Installing symfony/http-kernel (v4.3.3): Loading from cache
    - Installing symfony/routing (v4.3.3): Loading from cache
    - Installing symfony/finder (v4.3.3): Loading from cache
    - Installing symfony/filesystem (v4.3.3): Loading from cache
    - Installing symfony/dependency-injection (v4.3.3): Loading from cache
    - Installing symfony/config (v4.3.3): Loading from cache
    - Installing symfony/var-exporter (v4.3.3): Loading from cache
    - Installing psr/cache (1.0.1): Loading from cache
    - Installing symfony/cache-contracts (v1.1.5): Loading from cache
    - Installing symfony/cache (v4.3.3): Loading from cache
    - Installing symfony/framework-bundle (v4.3.3): Loading from cache
    - Installing sensio/framework-extra-bundle (v5.4.1): Loading from cache
    - Installing symfony/apache-pack (v1.0.1): Loading from cache
    - Installing symfony/dotenv (v4.3.3): Loading from cache
    - Installing symfony/expression-language (v4.3.3): Loading from cache
    - Installing symfony/inflector (v4.3.3): Loading from cache
    - Installing symfony/property-access (v4.3.3): Loading from cache
    - Installing symfony/options-resolver (v4.3.3): Loading from cache
    - Installing symfony/intl (v4.3.3): Loading from cache
    - Installing symfony/polyfill-intl-icu (v1.12.0): Loading from cache
    - Installing symfony/form (v4.3.3): Loading from cache
    - Installing symfony/http-client-contracts (v1.1.5): Loading from cache
    - Installing symfony/http-client (v4.3.3): Loading from cache
    - Installing monolog/monolog (1.24.0): Loading from cache
    - Installing symfony/monolog-bridge (v4.3.3): Loading from cache
    - Installing symfony/monolog-bundle (v3.4.0): Loading from cache
    - Installing doctrine/orm (v2.6.3): Loading from cache
    - Installing doctrine/doctrine-bundle (1.11.2): Loading from cache
    - Installing doctrine/doctrine-migrations-bundle (v2.0.0): Loading from cache
    - Installing symfony/orm-pack (v1.0.6): Loading from cache
    - Installing symfony/process (v4.3.3): Loading from cache
    - Installing symfony/security-core (v4.3.3): Loading from cache
    - Installing symfony/security-http (v4.3.3): Loading from cache
    - Installing symfony/security-guard (v4.3.3): Loading from cache
    - Installing symfony/security-csrf (v4.3.3): Loading from cache
    - Installing symfony/security-bundle (v4.3.3): Loading from cache
    - Installing symfony/serializer (v4.3.3): Loading from cache
    - Installing symfony/property-info (v4.3.3): Loading from cache
    - Installing webmozart/assert (1.5.0): Loading from cache
    - Installing phpdocumentor/reflection-docblock (4.3.1): Loading from cache
    - Installing symfony/serializer-pack (v1.0.2): Loading from cache
    - Installing swiftmailer/swiftmailer (v6.2.1): Loading from cache
    - Installing symfony/swiftmailer-bundle (v3.2.8): Loading from cache
    - Installing symfony/translation-contracts (v1.1.5): Loading from cache
    - Installing symfony/translation (v4.3.3): Loading from cache
    - Installing twig/twig (v2.11.3): Loading from cache
    - Installing symfony/twig-bridge (v4.3.3): Loading from cache
    - Installing symfony/twig-bundle (v4.3.3): Loading from cache
    - Installing symfony/validator (v4.3.3): Loading from cache
    - Installing psr/link (1.0.0): Loading from cache
    - Installing fig/link-util (1.0.0): Loading from cache
    - Installing symfony/web-link (v4.3.3): Loading from cache
    - Installing symfony/asset (v4.3.3): Loading from cache
    - Installing symfony/webpack-encore-bundle (v1.6.2): Loading from cache
    - Installing symfony/yaml (v4.3.3): Loading from cache
  Generating optimized autoload files
  ocramius/package-versions: Generating version class...
  ocramius/package-versions: ...done generating version class
  Executing script cache:clear [OK]
  Executing script assets:install public [OK]
  
  yarn run v1.17.3
  $ encore production --progress
  Running webpack ...
  
  98% after emitting SizeLimitsPlugin DONE  Compiled successfully in 5450ms                                                                                                                                                            1:09:20 PM
  
   I  18 files written to public/build
  Entrypoint app [big] = runtime.3c075ebb.js 0.6ea45216.css 0.376e4878.js app.f7e93431.css app.00b96fcb.js
  Entrypoint _tmp_copy = runtime.3c075ebb.js
  Done in 7.52s.
  </code></pre>
  
  <p>What i'am wondering about is and maybe its a help, in public/index.php are also debug "commands":</p>
  
  <pre><code>use App\Kernel;
  use Symfony\Component\Debug\Debug;
  use Symfony\Component\HttpFoundation\Request;
  
  require dirname(__DIR__).'/config/bootstrap.php';
  
  if ($_SERVER['APP_DEBUG']) {
      umask(0000);
  
      Debug::enable();
  }
  
  if ($trustedProxies = $_SERVER['TRUSTED_PROXIES'] ?? $_ENV['TRUSTED_PROXIES'] ?? false) {
      Request::setTrustedProxies(explode(',', $trustedProxies), Request::HEADER_X_FORWARDED_ALL ^ Request::HEADER_X_FORWARDED_HOST);
  }
  
  if ($trustedHosts = $_SERVER['TRUSTED_HOSTS'] ?? $_ENV['TRUSTED_HOSTS'] ?? false) {
      Request::setTrustedHosts([$trustedHosts]);
  }
  
  $kernel = new Kernel($_SERVER['APP_ENV'], (bool) $_SERVER['APP_DEBUG']);
  $request = Request::createFromGlobals();
  $response = $kernel-&gt;handle($request);
  $response-&gt;send();
  $kernel-&gt;terminate($request, $response);
  </code></pre>