## Problem When ruby is in release candidate or preview, `RUBY_PATCHLEVEL` ```RUBY_PATCHLEVEL``` is `-1`. ```-1```. Without parsing `RUBY_DESCRIPTION`, ```RUBY_DESCRIPTION```, its hard to tell using constant the right and absolute ruby version. ## Proposal Expose `RUBY_PATCHLEVEL_STR` RUBY_PATCHLEVEL_STR as a constant, just like `RUBY_VERSION` ```RUBY_VERSION``` or `RUBY_PATCHLEVEL`. ```RUBY_PATCHLEVEL```. So that, we can know the right ruby version, especially when its in preview or release candidate. This is also helpful when using gems that rely on `RUBY_PATCHLEVEL` ```RUBY_PATCHLEVEL``` and `RUBY_VERSION` ```RUBY_VERSION``` to serve the right experience. Example: Bundler, which validates gem installation by making sure right ruby is installed. Currently, we cannot install gems using 2.5.0preview1. ~~~ Your Ruby version is 2.5.0, but your Gemfile specified 2.5.0preview1 ~~~ This can be handled in bundler through some different wokraround, but I think by exposing `RUBY_PATCHLEVEL_STR`, ```RUBY_PATCHLEVEL_STR```, it will be helpful in building the appropriate solutions.