when running rake test --trace under ruby 2.2.0, inside rvm, on fedora 22 [x86_64], I'm getting:

/home/user/.rvm/gems/ruby-2.2.0/gems/fog-core-1.25.0/lib/fog/core/collection.rb:144: warning: circular argument reference - filters
** Invoke test (first_time)
** Execute test
** Invoke test:run (first_time)
** Execute test:run
** Invoke test:units (first_time)
** Invoke test:prepare (first_time)
** Invoke db:test:prepare (first_time)
** Invoke db:abort_if_pending_migrations (first_time)
** Invoke environment (first_time)
** Execute environment
rake aborted!
LoadError: cannot load such file -- test/unit/testcase