Update to drupal-org-drupal 8.0.0-rc2. For more information, see https://www.drupal.org/node/2598668

vendor/symfony/routing/Tests/Fixtures/validpattern.yml

@@ -1,13 +0,0 @@
-blog_show:
-    path:         /blog/{slug}
-    defaults:     { _controller: "MyBundle:Blog:show" }
-    host:         "{locale}.example.com"
-    requirements: { 'locale': '\w+' }
-    methods:      ['GET','POST','put','OpTiOnS']
-    schemes:      ['https']
-    condition:    'context.getMethod() == "GET"'
-    options:
-        compiler_class: RouteCompiler
-
-blog_show_inherited:
-    path:      /blog/{slug}