Gem.path + Gem.refresh not working in Gemfile

[mpapis]

$ rbx -v
rubinius 2.2.10.n264 (2.1.0 043cd9d2 2014-09-21 3.4.2 JI) [x86_64-linux-gnu]
# build from rbx master commit 043cd9d2cb91d668072aacf15ec8c79c82863b4a

$ gem -v
2.4.1
# installed form rubygems master commit f989db113b429d537b7ff315e8e1409904943618

$ gem list bundler
*** LOCAL GEMS ***
bundler (1.7.3, 1.6.2)

$ uname -a
Linux michal.papis 3.16.1-1.g90bc0f1-desktop #1 SMP PREEMPT Wed Aug 27 14:52:25 UTC 2014 (90bc0f1) x86_64 x86_64 x86_64 GNU/Linux

steps to reproduce:

git clone https://github.com/rvm/pluginator.git
cd pluginator
bundle install
bundle exec rake

here is --trace output: https://gist.github.com/mpapis/5d67bb86c8434633433a
here is travis build showing other rubies make it work https://travis-ci.org/rvm/pluginator/builds/35917726

[brixen]

Bundler versions post 1.6.3 (or 4) expose a rubygems threading bug. You are trying to force update bundler to a version that we do not install. Are you sure you're not hitting this rubygems threading bug?

[mpapis]

I have abandoned this approach, if you do not have time to investigate just close it