rails 5.0.0 when installing "nio4r" : Failed to build gem native extension

Solution for Fedora 64bit

sudo dnf install redhat-rpm-config

I am facing the same issue while I was trying to upgrade my Rails to V5.0.0, I follow this instruction and it works perfectly. Read the section "Install the Ruby DevKit" here >> http://jekyll-windows.juthilo.com/1-ruby-and-devkit/