Reproducible with vagrant 2.1.3, 2.1.4 and 2.1.5.
$ git log --oneline -1 347e0849 (HEAD -> master, origin/master, origin/HEAD) Send Thumbor-Request-Id in haproxy response $ vagrant -v Vagrant 2.1.3 $ vagrant up Vagrant failed to initialize at a very early stage: There was an error loading a Vagrantfile. The file being loaded and the error message are shown below. This is usually caused by a syntax error. Path: /Users/z/Documents/gerrit/mediawiki/vagrant/Vagrantfile Line number: 48 Message: NameError: uninitialized constant MediaWikiVagrant::Environment
Workaround is to install Vagrant 2.1.2.