Sending files to Gemnasium: 500 Internal Server Error: invalid character 'S' looking for beginning of value

[nile1985]

During deployment project with Rails 4.2 I got an error: 500 Internal Server Error: invalid character 'S' looking for beginning of value. I've created rake task which run command to push dependency files:

namespace :deploy do
  desc 'Push dependency files to gemnasium'
  task :gemnasium do
    on primary :db do
      execute " cd #{fetch(:release_path)} && /usr/bin/gemnasium dependency_files push -f=Gemfile,Gemfile.lock"
    end if fetch(:gemnasium)
  end
end

When I tried to deploy at the first time on target server task returned 500 Internal Server Error. I think that invalid character 'S' connected with first symbol in Gemfile: source 'http://rubygems.org'. But at the second and later attempts without any changes all seems OK and files sends to Gemnasium.

[gravis]

Could you send more details on details on http://support.gemnasium.com please?
Could you also make sure the env vars are correctly set, especially REVISION?
We'd like to check our logs with your project slug.

Thanks