diff --git a/lib/behat/lib.php b/lib/behat/lib.php
index b1a747a31f3..70543f04184 100644
--- a/lib/behat/lib.php
+++ b/lib/behat/lib.php
@@ -70,3 +70,60 @@ function behat_error($errorcode, $text = '') {
     testing_error($errorcode, $text);
 }
 
+/**
+ * PHP errors handler to use when running behat tests.
+ *
+ * Adds specific CSS classes to identify
+ * the messages.
+ *
+ * @param int $errno
+ * @param string $errstr
+ * @param string $errfile
+ * @param int $errline
+ * @param array $errcontext
+ * @return bool
+ */
+function behat_error_handler($errno, $errstr, $errfile, $errline, $errcontext) {
+    global $OUTPUT;
+
+    // Only after something has been writen.
+    if (!$OUTPUT->has_started()) {
+        return false;
+    }
+
+    // If is preceded by an @ we don't show it.
+    if (!error_reporting()) {
+        return true;
+    }
+
+    // Using the default one in case there is a fatal catchable error.
+    default_error_handler($errno, $errstr, $errfile, $errline, $errcontext);
+
+    switch ($errno) {
+        case E_USER_ERROR:
+            $errnostr = 'Fatal error';
+            break;
+        case E_WARNING:
+        case E_USER_WARNING:
+            $errnostr = 'Warning';
+            break;
+        case E_NOTICE:
+        case E_USER_NOTICE:
+        case E_STRICT:
+            $errnostr = 'Notice';
+            break;
+        case E_RECOVERABLE_ERROR:
+            $errnostr = 'Catchable';
+            break;
+        default:
+            $errnostr = 'Unknown error type';
+    }
+
+    // Wrapping the output.
+    echo '<div class="phpdebugmessage">' . PHP_EOL;
+    echo "$errnostr: $errstr in $errfile on line $errline" . PHP_EOL;
+    echo '</div>';
+
+    // Also use the internal error handler so we keep the usual behaviour.
+    return false;
+}
diff --git a/lib/setup.php b/lib/setup.php
index a5db7803e93..213ac7030ed 100644
--- a/lib/setup.php
+++ b/lib/setup.php
@@ -455,6 +455,12 @@ if (!PHPUNIT_TEST or PHPUNIT_UTIL) {
     set_error_handler('default_error_handler', E_ALL | E_STRICT);
 }
 
+// Acceptance tests needs special output to capture the errors.
+if (!empty($CFG->originaldataroot) && !defined('BEHAT_RUNNING')) {
+    require_once(__DIR__ . '/behat/lib.php');
+    set_error_handler('behat_error_handler', E_ALL | E_STRICT);
+}
+
 // If there are any errors in the standard libraries we want to know!
 error_reporting(E_ALL | E_STRICT);
 
diff --git a/lib/tests/behat/behat_hooks.php b/lib/tests/behat/behat_hooks.php
index a8893482ae7..4fb968e5e93 100644
--- a/lib/tests/behat/behat_hooks.php
+++ b/lib/tests/behat/behat_hooks.php
@@ -132,6 +132,9 @@ class behat_hooks extends behat_base {
         // Assing valid data to admin user (some generator-related code needs a valid user).
         $user = $DB->get_record('user', array('username' => 'admin'));
         session_set_user($user);
+
+        // Start always in the the homepage.
+        $this->getSession()->visit($this->locate_path('/'));
     }
 
     /**
@@ -178,4 +181,73 @@ class behat_hooks extends behat_base {
         }
     }
 
+    /**
+     * Internal step definition to find exceptions, debugging() messages and PHP debug messages.
+     *
+     * Part of behat_hooks class as is part of the testing framework, is auto-executed
+     * after each step so no features will splicitly use it.
+     *
+     * @Given /^I look for exceptions$/
+     * @see Moodle\BehatExtension\Tester\MoodleStepTester
+     */
+    public function i_look_for_exceptions() {
+
+        // Exceptions.
+        if ($errormsg = $this->getSession()->getPage()->find('css', '.errorbox p.errormessage')) {
+
+            // Getting the debugging info and the backtrace.
+            $errorinfoboxes = $this->getSession()->getPage()->findAll('css', 'div.notifytiny');
+            $errorinfo = $this->get_debug_text($errorinfoboxes[0]->getHtml()) . "\n" .
+                $this->get_debug_text($errorinfoboxes[1]->getHtml());
+
+            $msg = "Moodle exception: " . $errormsg->getText() . "\n" . $errorinfo;
+            throw new \Exception(html_entity_decode($msg));
+        }
+
+        // Debugging messages.
+        if ($debuggingmessages = $this->getSession()->getPage()->findAll('css', '.debuggingmessage')) {
+            $msgs = array();
+            foreach ($debuggingmessages as $debuggingmessage) {
+                $msgs[] = $this->get_debug_text($debuggingmessage->getHtml());
+            }
+            $msg = "debugging() message/s found:\n" . implode("\n", $msgs);
+            throw new \Exception(html_entity_decode($msg));
+        }
+
+        // PHP debug messages.
+        if ($phpmessages = $this->getSession()->getPage()->findAll('css', '.phpdebugmessage')) {
+
+            $msgs = array();
+            foreach ($phpmessages as $phpmessage) {
+                $msgs[] = $this->get_debug_text($phpmessage->getHtml());
+            }
+            $msg = "PHP debug message/s found:\n" . implode("\n", $msgs);
+            throw new \Exception(html_entity_decode($msg));
+        }
+
+        // Any other backtrace.
+        $backtracespattern = '/(line [0-9]* of [^:]*: call to [\->&;:a-zA-Z_\x7f-\xff][\->&;:a-zA-Z0-9_\x7f-\xff]*)/';
+        if (preg_match_all($backtracespattern, $this->getSession()->getPage()->getContent(), $backtraces)) {
+            $msgs = array();
+            foreach ($backtraces[0] as $backtrace) {
+                $msgs[] = $backtrace . '()';
+            }
+            $msg = "Other backtraces found:\n" . implode("\n", $msgs);
+            throw new \Exception(htmlentities($msg));
+        }
+    }
+
+    /**
+     * Converts HTML tags to line breaks to display the info in CLI
+     *
+     * @param string $html
+     * @return string
+     */
+    protected function get_debug_text($html) {
+
+        // Replacing HTML tags for new lines and keeping only the text.
+        $notags = preg_replace('/<+\s*\/*\s*([A-Z][A-Z0-9]*)\b[^>]*\/*\s*>*/i', "\n", $html);
+        return preg_replace("/(\n)+/s", "\n", $notags);
+    }
+
 }
diff --git a/lib/weblib.php b/lib/weblib.php
index b61f1bce46f..1985b7ec7f7 100644
--- a/lib/weblib.php
+++ b/lib/weblib.php
@@ -2792,7 +2792,7 @@ function debugging($message = '', $level = DEBUG_NORMAL, $backtrace = null) {
             if (CLI_SCRIPT) {
                 echo "++ $message ++\n$from";
             } else {
-                echo '<div class="notifytiny">' . $message . $from . '</div>';
+                echo '<div class="notifytiny debuggingmessage">' . $message . $from . '</div>';
             }
 
         } else {