It is probably broken with ruby 2.0

[JelF]

It fails to run in development environment with this version, so it may be an issue with my app.
Howewer, it fails (https://travis-ci.org/JelF/xconfig/jobs/98467383)
Ruby 2.0 seems to be outdated enough, that you can simply drop it. Please, add something like spec.required_ruby_version = '~> 2.1' inside your gemspec
PS jruby-9000 works