uninitialized constant Timer::Timers - ruby

Question

I am trying to do a task periodically, and I have seen this. I have installed the gem 'timer' using bundle install
and then here is my Timer class:
require 'timers'
class Timer
def initialize
timers = Timers::Group.new
timers.every(5) { puts "Another 5 seconds" }
end
end
but when i run the class i face with the error:
`require': cannot load such file -- timers (LoadError)
and here is the output of my gem env :
RubyGems Environment:
- RUBYGEMS VERSION: 2.5.1
- RUBY VERSION: 2.3.0 (2015-12-25 patchlevel 0) [x86_64-linux]
- INSTALLATION DIRECTORY: /usr/local/rvm/gems/ruby-2.3.0
- USER INSTALLATION DIRECTORY: /home/ubuntu/.gem/ruby/2.3.0
- RUBY EXECUTABLE: /usr/local/rvm/rubies/ruby-2.3.0/bin/ruby
- EXECUTABLE DIRECTORY: /usr/local/rvm/gems/ruby-2.3.0/bin
- SPEC CACHE DIRECTORY: /home/ubuntu/.gem/specs
- SYSTEM CONFIGURATION DIRECTORY: /etc
- RUBYGEMS PLATFORMS:
- ruby
- x86_64-linux
- GEM PATHS:
- /usr/local/rvm/gems/ruby-2.3.0
- /usr/local/rvm/gems/ruby-2.3.0#global
- GEM CONFIGURATION:
- :update_sources => true
- :verbose => true
- :backtrace => false
- :bulk_threshold => 1000
- "gem" => "--no-document"
- "install" => "--no-rdoc --no-ri"
- "update" => "--no-rdoc --no-ri"
- REMOTE SOURCES:
- https://rubygems.org/
- SHELL PATH:
- /home/ubuntu/.nvm/versions/node/v4.4.3/bin
- /usr/local/rvm/gems/ruby-2.3.0/bin
- /usr/local/rvm/gems/ruby-2.3.0#global/bin
- /usr/local/rvm/rubies/ruby-2.3.0/bin
- /mnt/shared/bin
- /home/ubuntu/workspace/node_modules/.bin
- /home/ubuntu/bin
- /usr/local/sbin
- /usr/local/bin
- /usr/sbin
- /usr/bin
- /sbin
- /bin
- /mnt/shared/sbin
- /opt/gitl
- /opt/go/bin
- /mnt/shared/c9/app.nw/bin
- /usr/local/rvm/bin

Answer 1

This error tells us the code you are trying to load is not on the LOAD_PATH. When you require 'timers' you are telling Ruby to search the LOAD_PATH for a file called timers.rb and it cannot be located. Installing the gem does not put the gem on your load path.
It sounds like you are not using Bundler to manage your dependencies. Once you start depending on 3rd party code, you really should start using Bundler. It will put all the code you need on the LOAD_PATH and provide a ton of other helpful features.
If you are just messing around, one option you can do is:
ruby -I <path/to/timers/lib>
This will allow Ruby to locate timers.rb