added an exception for failed processes

src/Symfony/Component/Process/Exception/ExceptionInterface.php

@@ -0,0 +1,21 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Process\Exception;
+
+/**
+ * Marker Interface for the Process Component.
+ *
+ * @author Johannes M. Schmitt <schmittjoh@gmail.com>
+ */
+interface ExceptionInterface
+{
+}

src/Symfony/Component/Process/Exception/ProcessFailedException.php

@@ -0,0 +1,40 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Process\Exception;
+
+use Symfony\Component\Process\Process;
+
+/**
+ * Exception for failed processes.
+ *
+ * @author Johannes M. Schmitt <schmittjoh@gmail.com>
+ */
+class ProcessFailedException extends RuntimeException
+{
+    private $process;
+
+    public function __construct(Process $process)
+    {
+        if ($process->isSuccessful()) {
+            throw new \InvalidArgumentException('Expected a failed process, but the given process was successful.');
+        }
+
+        parent::__construct(sprintf('The command "%s" failed.'."\n\nOutput:\n================\n".$process->getOutput()."\n\nError Output:\n================\n".$process->getErrorOutput()));
+
+        $this->process = $process;
+    }
+
+    public function getProcess()
+    {
+        return $this->process;
+    }
+}

src/Symfony/Component/Process/Exception/RuntimeException.php

@@ -0,0 +1,21 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Process\Exception;
+
+/**
+ * RuntimeException for the Process Component.
+ *
+ * @author Johannes M. Schmitt <schmittjoh@gmail.com>
+ */
+class RuntimeException extends \RuntimeException implements ExceptionInterface
+{
+}