benchmark

$ irb
irb(main):001:0> require 'rubygems'
=> true
irb(main):002:0> require 'benchmark'
=> true
irb(main):003:0> Benchmark.bmbm do |x|
irb(main):004:1*   x.report('Gem.clear_paths') { Gem.clear_paths }
irb(main):005:1>   x.report("Gem.find_files('rubygems_plugin')") do
irb(main):006:2*     Gem.clear_paths
irb(main):007:2>     Gem.find_files 'rubygems_plugin'
irb(main):008:2>   end
irb(main):009:1>   x.report("Gem.latest_load_paths.map{...}") do
irb(main):010:2*     Gem.clear_paths
irb(main):011:2>     Gem.latest_load_paths.map do |path|
irb(main):012:3*       path = path+'/rubygems_plugin.rb'
irb(main):013:3>       path if File.exists? path
irb(main):014:3>     end.compact
irb(main):015:2>       
irb(main):016:2*   end
irb(main):017:1> end
Rehearsal ---------------------------------------------------------------------
Gem.clear_paths                     0.000000   0.000000   0.000000 (  0.000012)
Gem.find_files('rubygems_plugin')   0.070000   0.000000   0.070000 (  0.088658)
Gem.latest_load_paths.map{...}      0.070000   0.010000   0.080000 (  0.079032)
------------------------------------------------------------ total: 0.150000sec

                                        user     system      total        real
Gem.clear_paths                     0.000000   0.000000   0.000000 (  0.000015)
Gem.find_files('rubygems_plugin')   0.060000   0.010000   0.070000 (  0.067844)
Gem.latest_load_paths.map{...}      0.070000   0.000000   0.070000 (  0.067646)

checkout_rubygems_find_plugin_code

$ svn checkout http://rubygems.rubyforge.org/svn
...
$ cd svn/trunk/lib/
...
$ rgrep rubygems_plugin --exclude-dir=\.svn .
...
./rubygems.rb:plugins = Gem.find_files 'rubygems_plugin'

$ rgrep 'self.find_files(' --exclude-dir=\.svn -B 3 . 
...
./rubygems.rb-  # Note that find_files will return all files even if they are from different
./rubygems.rb-  # versions of the same gem.
./rubygems.rb-
./rubygems.rb:  def self.find_files(path)

gem_rdoc_sinatra_stack

$ sudo gem rdoc sinatra --backtrace
ERROR:  While executing gem ... (SystemStackError)
    stack level too deep
	/usr/lib/ruby/gems/1.8/gems/yard-0.5.2/lib/rubygems_plugin.rb:19:in `has_rdoc?'
	/usr/lib/ruby/gems/1.8/gems/yard-0.4.0/lib/rubygems_plugin.rb:77:in `install_ri_yard_orig'
	/usr/lib/ruby/gems/1.8/gems/yard-0.4.0/lib/rubygems_plugin.rb:77:in `install_ri_yard_orig'
	/usr/lib/ruby/gems/1.8/gems/yard-0.5.2/lib/rubygems_plugin.rb:79:in `install_ri'
	/usr/local/lib/site_ruby/1.8/rubygems/doc_manager.rb:109:in `generate_ri'
	/usr/local/lib/site_ruby/1.8/rubygems/commands/rdoc_command.rb:61:in `execute'
	/usr/local/lib/site_ruby/1.8/rubygems/commands/rdoc_command.rb:60:in `each'
	/usr/local/lib/site_ruby/1.8/rubygems/commands/rdoc_command.rb:60:in `execute'
	/usr/local/lib/site_ruby/1.8/rubygems/command.rb:257:in `invoke'
	/usr/local/lib/site_ruby/1.8/rubygems/command_manager.rb:132:in `process_args'
	/usr/local/lib/site_ruby/1.8/rubygems/command_manager.rb:102:in `run'
	/usr/local/lib/site_ruby/1.8/rubygems/gem_runner.rb:58:in `run'
	/usr/bin/gem:21

possible_fix.rb

plugins = Gem.latest_load_paths.map do |path|
      path = path+'/rubygems_plugin.rb'
      path if File.exists? path
    end.compact

plugins.each do |plugin|
  begin
    load plugin
  rescue => e
    warn "error loading #{plugin.inspect}: #{e.message} (#{e.class})"
  end
end

rubygems_snippet.rb

plugins = Gem.find_files 'rubygems_plugin'

plugins.each do |plugin|
  begin
    load plugin
  rescue => e
    warn "error loading #{plugin.inspect}: #{e.message} (#{e.class})"
  end
end