Поменял структуру проекта для расширения задачи с приемом

vendor/symfony/polyfill-ctype/composer.json

@@ -16,7 +16,7 @@
         }
     ],
     "require": {
-        "php": ">=7.1"
+        "php": ">=7.2"
     },
     "provide": {
         "ext-ctype": "*"

vendor/symfony/yaml/Inline.php

@@ -353,11 +353,18 @@ class Inline
         ++$i;
 
         // [foo, bar, ...]
+        $lastToken = null;
         while ($i < $len) {
             if (']' === $sequence[$i]) {
                 return $output;
             }
             if (',' === $sequence[$i] || ' ' === $sequence[$i]) {
+                if (',' === $sequence[$i] && (null === $lastToken || 'separator' === $lastToken)) {
+                    $output[] = null;
+                } elseif (',' === $sequence[$i]) {
+                    $lastToken = 'separator';
+                }
+
                 ++$i;
 
                 continue;
@@ -401,6 +408,7 @@ class Inline
 
             $output[] = $value;
 
+            $lastToken = 'value';
             ++$i;
         }
 
@@ -716,8 +724,13 @@ class Inline
                     case Parser::preg_match('/^(-|\+)?[0-9][0-9_]*(\.[0-9_]+)?$/', $scalar):
                         return (float) str_replace('_', '', $scalar);
                     case Parser::preg_match(self::getTimestampRegex(), $scalar):
-                        // When no timezone is provided in the parsed date, YAML spec says we must assume UTC.
-                        $time = new \DateTimeImmutable($scalar, new \DateTimeZone('UTC'));
+                        try {
+                            // When no timezone is provided in the parsed date, YAML spec says we must assume UTC.
+                            $time = new \DateTimeImmutable($scalar, new \DateTimeZone('UTC'));
+                        } catch (\Exception $e) {
+                            // Some dates accepted by the regex are not valid dates.
+                            throw new ParseException(\sprintf('The date "%s" could not be parsed as it is an invalid date.', $scalar), self::$parsedLineNumber + 1, $scalar, self::$parsedFilename, $e);
+                        }
 
                         if (Yaml::PARSE_DATETIME & $flags) {
                             return $time;