Red Hat Enterprise Linux 7 contains Ruby version 2.0.0. The system paths for libraries and gems have changed from Red Hat Enterprise Linux 5.

For the information on how to migrate Ruby from Red Hat Enterprise Linux 5 to Red Hat Enterprise Linux 7, see the Migration Guide for Ruby from RHEL 6 to RHEL7: [link:https://access.redhat.com/site/articles/790123]

Additional incompatibilities include, but are not limited to:
 * String#slice! changed its behavior in some cases, as it had unintentional bugs that have been fixed.
 * String#to_i, String#hex and String#oct no longer accept a sequence of underscores (`__') as a part of a number.
 * Date.parse '##.##.##' (where each '#' is a digit) is now taken as 'YY.MM.DD' instead of 'MM.DD.YY'.
 * The return value of StringIO#each_byte changed from nil to self.
 * String#intern now raises SecurityError when $SAFE level is greater than zero.
 * The constructor of Digest::MD5 does no longer take an initial string to feed.
 * Tk::X_Scrollable (Y_Scrollable) is renamed to Tk::XScrollable

For more details, read the official NEWS and Changelog for each minor release:
 * http://svn.ruby-lang.org/repos/ruby/tags/v1_8_7/NEWS
 * http://svn.ruby-lang.org/repos/ruby/tags/v1_8_7/ChangeLog
 * http://svn.ruby-lang.org/repos/ruby/tags/v1_8_6/NEWS
 * http://svn.ruby-lang.org/repos/ruby/tags/v1_8_6/ChangeLog

The files and directories listed below are not owned by any RPM package, or they are owned by an RPM package that is not signed by Red Hat. These packages need to be rebuilt and reinstalled in order to work with Ruby 2.0.0.
