In case you want to use pry with an older version of Ruby, you can try the following configurations.

Ruby 1.8.7

Your pry version must not be greater than 0.9.10.

gem 'pry', '=0.9.10'
gem 'ruby-debug',...

You're better off using debugger-ruby_core_source:

gem install debugger-ruby_core_source

If you can't do this, try the following.

Here is how to fix the following error when installing the debugger gem fails:

Gem::Instal...

The Ruby Koans walk you along the path to enlightenment in order to learn Ruby. The goal is to learn the Ruby language, syntax, structure, and some common functions and libraries. We also teach you culture. Testing is not just something we pay lip...

If your project uses another version than your default Ruby, RubyMine will give you incorrect inspections, for example.\
Here is how to switch which Ruby you use in RubyMine.

1. File → Settings (Or press Ctrl+Alt+S)
2. Select "Ruby SDK and Gem...

Using Ruby 1.8.7 you will not be able to use the maximum versions Rubygems 1.8.30 and Bundler 1.17.3 with https://rubygems.org/ anymore. This is a result of a server certificate on December 5th, 2020. The resulting errors will...

You can install rubygems 3.0.8 (released on February 18, 2020) to keep all the Gem::Specification#rubyforge_project deprecation warnings away from your development log. With Rubygems >= 3.1 this deprecation warning was introduced. While main...

I followed this nice guide Connecting to MSSQL with Ruby on Ubuntu - lambie.org until I ran in the following errors:

irb(main):001:0> require "dbi"; ...

rbenv

To check which rubygems versions your different rbenv rubys are using, you can use this small bash script:

for i in $(rbenv versions --bare); do rbenv shell "${i}"; echo -n "ruby ${i} has gem version: "; gem -v; done

RVM

``...

RubySpec is a project to write a complete, executable specification for the Ruby programming language.