CODEWITHSUNDEEP
rubylinuxrubygemsnokogiri
Stephen Tetreault
Stephen Tetreault

Reputation: 787

Nokogiri Ruby 'require' Issues

I'm new to Ruby and I'm having a lot of trouble trying to use Nokogiri. I've been trying to find a resolution for hours now, so any help is appreciated. I tried searching for and using solutions from other related SO posts before caving and posting my own. When I run ruby -v I get: ruby 1.8.7 (2011-06-30 patchlevel 352) [x86_64-linux]

(Edit: I have updated ruby with updates-alternatives --config ruby and selected /usr/bin/ruby1.9.1 but when I do ruby -v it is now showing version 1.9.3 WTF am I doing wrong here?)

I have a new project directory at ~/workspace/ruby/rubycrawler/ and I used Bundler to install nokogiri, which installed correctly: 

Using mini_portile (0.5.2)
Using nokogiri (1.6.1)
Using bundler (1.5.1)
Your bundle is complete!

Running bundle show nokogiri returns /var/lib/gems/1.9.1/gems/nokogiri-1.6.1.

In the directory I'm running the script from I have a simple html file named "index.html". The script I'm trying to run is even simpler (or so I thought):

require 'nokogiri'
page = Nokogiri::HTML(open("index.html"))
puts page.class    # Nokogiri::HTML::Document

The error is rubycrawler.rb:1:in 'require': no such file to load -- nokogiri (LoadError).

I also added require 'rubygems' even though I read it isn't needed for 1.9+ and still no luck.

A lot of searching shows "Did you put this gem in your Gemfile?". So I generate a Gemfile and add gem 'nokogiri'. I try running the small script again and get the same error. I read "Try deleting Gemfile.lock." so I did but still couldn't get it to work. I then read to try testing it out in irb so I tested "open-uri" and "nokogiri" and here's what I got:

irb(main):001:0> require 'open-uri'
=> true
irb(main):003:0> require 'nokogiri'
LoadError: no such file to load -- nokogiri

I'm really having a lot of trouble figuring this out, so really any help at all is really appreciated.

Upvotes: 0

Views: 766

Answers (2)

Eugene
Eugene

Reputation: 4879

In addition to Kent's answer, I would recommend switching to RVM instead of using the system installed ruby. System rubies tend to be horribly out of date, especially when it comes to important things like features and security updates. It might not help you in your current situation, but it would be well worth the time. If you are unfamiliar: http://rvm.io

Upvotes: 1

Kent Rancourt
Kent Rancourt

Reputation: 1595

Ruby tools like RVM, Bundler, etc., to the novice, appear to do a lot of magic, but really, there is no magic to them. The key here lies in what Bundler actually does for you. It manages a manifest of dependencies, BUT at runtime, those dependencies STILL have to get loaded somehow, and my gut feeling is that is what is not happening here.

Regardless of what version of Ruby you are using, if you are using Bundler, there's an easy way to do this. Precede the command that starts your program with "bundle exec" and that will make Bundler edit Ruby's load path so that it includes all the things in the manifest (Gemfile.lock).

For example:

$ bundle exec ruby foo.rb

A additional note for anyone using RVM: RVM generally will modify the shebangs in the scripts that launch programs like "ruby" or "rake" so that they use the "ruby_no_exec" shell (or similar) instead of the plain old "ruby" shell. That alternate shell is Bundler-aware and makes it generally unnecessary to type "bundle exec," but since the OP is using system Ruby, that's not applicable and commands should be manually prefixed with "bundle exec".

Hope this helps!

Upvotes: 1

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