forward the parse error to the calling code

Author: xabbuh

Loader/XmlFileLoader.php

@@ -383,7 +383,7 @@ private function parseFileToDOM($file)
         try {
             $dom = XmlUtils::loadFile($file, [$this, 'validateSchema']);
         } catch (\InvalidArgumentException $e) {
-            throw new InvalidArgumentException(sprintf('Unable to parse file "%s".', $file), $e->getCode(), $e);
+            throw new InvalidArgumentException(sprintf('Unable to parse file "%s": %s', $file, $e->getMessage()), $e->getCode(), $e);
         }
 
         $this->validateExtensions($dom, $file);

Loader/YamlFileLoader.php

@@ -666,7 +666,7 @@ protected function loadFile($file)
         try {
             $configuration = $this->yamlParser->parseFile($file, Yaml::PARSE_CONSTANT | Yaml::PARSE_CUSTOM_TAGS);
         } catch (ParseException $e) {
-            throw new InvalidArgumentException(sprintf('The file "%s" does not contain valid YAML.', $file), 0, $e);
+            throw new InvalidArgumentException(sprintf('The file "%s" does not contain valid YAML: %s', $file, $e->getMessage()), 0, $e);
         } finally {
             restore_error_handler();
         }