Redmine

Hi,

I've been trying to install Redmine on a new RHEL 7 installation, but continue to receive the following error:

[redmine@localhost redmine-3.1.0]$ bundle install --without development test
Fetching gem metadata from https://rubygems.org/........./usr/share/gems/gems/psych-2.0.0/lib/psych.rb:98: warning: already initialized constant Psych::VERSION
/usr/share/ruby/psych.rb:98: warning: previous definition of VERSION was here
/usr/share/gems/gems/psych-2.0.0/lib/psych.rb:101: warning: already initialized constant Psych::LIBYAML_VERSION
/usr/share/ruby/psych.rb:101: warning: previous definition of LIBYAML_VERSION was here

Fetching version metadata from https://rubygems.org/..
Resolving dependencies.........
Using rake 10.4.2
Using i18n 0.7.0
Installing json 1.8.3 with native extensions

Gem::Ext::BuildError: ERROR: Failed to build gem native extension.

/usr/bin/ruby -r ./siteconf20150728-18120-1q91igb.rb extconf.rb
mkmf.rb can't find header files for ruby at /usr/share/include/ruby.h

extconf failed, exit code 1

Gem files will remain installed in /home/redmine/.gem/ruby/gems/json-1.8.3 for inspection.
Results logged to /home/redmine/.gem/ruby/extensions/x86_64-linux/json-1.8.3/gem_make.out
An error occurred while installing json (1.8.3), and Bundler cannot continue.
Make sure that `gem install json -v '1.8.3'` succeeds before bundling.

After researching this error, it seems like I just need to install ruby-devel to fix the issue. The problem is that the RHEL repositories don't have ruby-devel available. Has anyone else run into/fixed this issue? Thanks!