failure to coerce

ruby 2.1 getting a coercion error when trying middleman 4.0.0.alpha.2
.rvm/gems/ruby-2.1.1/gems/middleman-core-4.0.0.alpha.2/lib/middleman-core/load_paths.rb:41:in `findup': undefined method `exist?' for "./midtest/test1Gemfile":String (NoMethodError)
fixed