OpenNebula

Can you send us the error you're getting. I can successfully run install_gems script. Also, thin version 1.7.0 supports ruby 2.0.0:

https://rubygems.org/gems/thin/versions/1.7.0

Please see also https://github.com/OpenNebula/addon-installgems/pull/13
Error occured when building rpm with addon-installgems
AFAIR installing thin >= 1.7.0 (as a dep for the build) requires/installs a rack version > 2.0.0 which then breaks compatibility which ruby < 2.2.0
more details
rack < 2.0.0 was already installed built and rpm-packaged, but thin installation/build failed when trying to install rack >= 2.0.0 (the installed and packaged rack version was not sufficient for installing thin)

install_gems script specifies rack < 2.0.0 when ruby < 2.2.0. I've tested it in CentOS and Ubuntu 14.04, it works OK. Can you try the new version? To do that you can download these three files to the same directory and execute install_gems (assuming you're using CentOS 7):

• https://github.com/OpenNebula/one/blob/master/share/install_gems/install_gems
• https://raw.githubusercontent.com/OpenNebula/one/master/share/install_gems/Gemfile
• https://raw.githubusercontent.com/OpenNebula/one/master/share/install_gems/CentOS7/Gemfile.lock

The versions installed are fixed in Gemfile.lock

install_gems works as expected but addon-installgems fails.
see also https://github.com/OpenNebula/addon-installgems/issues/14