rails installation errors

After I run

sudo gem install rails --version 3.0.7

for installing rails on Mac. It got some errors. Could anybody help me how to solve it?

Successfully installed rails-3.0.7
24 gems installed
开发者_运维技巧Installing ri documentation for activesupport-3.0.7...
Installing ri documentation for builder-2.1.2...
ERROR:  While generating documentation for builder-2.1.2
... MESSAGE:   Unhandled special: Special: type=17, text="<!-- HI -->"
... RDOC args: --ri --op /Library/Ruby/Gems/1.8/doc/builder-2.1.2/ri --title Builder -- Easy XML Building --main README --line-numbers lib CHANGES Rakefile README doc/releases/builder-1.2.4.rdoc doc/releases/builder-2.0.0.rdoc doc/releases/builder-2.1.1.rdoc --title builder-2.1.2 Documentation --quiet

you won't need that documentation anyway, so:

sudo gem install rails --version 3.0.7 --no-ri --no-rdoc

If you want the Rdoc/ri documentation, you will need to install a later version of version of Rdoc/ri. The solution is documented here:

To quote from Mr. Okwaro, "... first uninstall the Rails version you just installed with no Rdoc/ri data:

sudo gem uninstall rails –version 3.0.7

Install the latest version of the rdoc-data gem. This will install ri data for core and stdlib:

gem install rdoc-data

Then run:

rdoc-data –install

In case you want rdoc-data for all your gems run (not necessary.. takes a while if you have as many gems as i do):

gem rdoc –all –overwrite

To install ri data for RDoc 2.5+ run:

rdoc-data

Now you can install your Rails version and it will successfully install all the rdoc-data too.

sudo gem install rails