This is the code I've used in order to compile the gem "net-ldap" in branch master from https://github.com/RoryO/ruby-net-ldap . If you use `gem install "net-ldap`, you will install the v0.1.1 version which don't supports Ruby 1.9.2 . When the developer

compile_net_ldap.rb

# Step 0: Add (temporary) the following gems to your application Gemfile
group :development, :test do
  gem "hoe"
  gem "rspec"
end

# ... and then ...
bundle install

# Step 1: Download the tarball from https://github.com/RoryO/ruby-net-ldap and untar it in vendor/gems/ruby-net-ldap folder

# Step 2: Go to the main folder of your Rails 3 application
cd vendor/gems/ruby-net-ldap

# Step 3: There's a bug with Psych parser with bundler 1.0.10. So add this line at the bottom of Rakefile (before require rubygems) and save the file:
# require 'psych'

# Step 4: Build the gem
rake clean
rake debug_gem | grep -v "(in " > `basename \`pwd\``.gemspec
rake build_manifest
rake gem

# Step 5: Add your shining homemade gem to your Gemfile
gem "net-ldap", :path => "vendor/gems/ruby-net-ldap/pkg/" , :require => 'net/ldap'
bundle install