# Updating to Rails 3 on Mac OS X **URL:** \ **Category:** Rails\ **Created:** [August 30, 2010, 12:21am UTC](https://www.ruby-forum.com/t/updating-to-rails-3-on-mac-os-x/194080 "2010-08-30T00:21:59Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![nobosh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/ecb155/32.png) [@nobosh](https://www.ruby-forum.com/u/nobosh)\ **Post date:** [August 30, 2010, 12:21am UTC](https://www.ruby-forum.com/t/updating-to-rails-3-on-mac-os-x/194080/1 "2010-08-30T00:21:59Z")
Hello, I’m working to install Rails 3 (pre) on my Mac, from the Rails blog post it says to run: gem install rails --pre After running that command I get the following errors: WARNING: Installing to ~/.gem since /Library/Ruby/Gems/1.8 and /usr/bin aren’t both writable. WARNING: You don’t have /Users/myusername/.gem/ruby/1.8/bin in your PATH, gem executables will not run. ERROR: Error installing rails: activemodel requires builder (~\> 2.1.2, runtime) was there a step required before running the install that wasn’t mentioned on the blog post? > **[Rails 3.0: Release candidate 2](https://rubyonrails.org/2010/8/24/rails-3-0-release-candidate-2)** > > The release candidate process is progressing as planned. This second candidate has very few changes over the first, which means that unless any blockers are discovered with this release, we’re targeting the final release of Rails 3.0 for this... Thanks ---
**Author:** ![nobosh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/ecb155/32.png) [@nobosh](https://www.ruby-forum.com/u/nobosh)\ **Post date:** [August 30, 2010, 1:01am UTC](https://www.ruby-forum.com/t/updating-to-rails-3-on-mac-os-x/194080/2 "2010-08-30T01:01:47Z")
Update 3, after getting all the dependencies installed, it’s still erroring: sudo gem install rails --pre Successfully installed rails-3.0.0.rc2 1 gem installed Installing ri documentation for rails-3.0.0.rc2… File not found: lib Ideas? ---
**Author:** ![nobosh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/ecb155/32.png) [@nobosh](https://www.ruby-forum.com/u/nobosh)\ **Post date:** [August 30, 2010, 12:48am UTC](https://www.ruby-forum.com/t/updating-to-rails-3-on-mac-os-x/194080/3 "2010-08-30T00:48:19Z")
Running “sudo gem install rails --pre” seemed to make it happier, only error’d now with: ERROR: Error installing rails: activemodel requires builder (~\> 2.1.2, runtime) ---
**Author:** ![nobosh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/ecb155/32.png) [@nobosh](https://www.ruby-forum.com/u/nobosh)\ **Post date:** [August 30, 2010, 1:32am UTC](https://www.ruby-forum.com/t/updating-to-rails-3-on-mac-os-x/194080/4 "2010-08-30T01:32:14Z")
nobosh wrote: > Update 3, after getting all the dependencies installed, it’s still > erroring: > > sudo gem install rails --pre > Successfully installed rails-3.0.0.rc2 > 1 gem installed > Installing ri documentation for rails-3.0.0.rc2… > File not found: lib > > Ideas? It looks like it actually installed, it just had trouble building ri/rdocs. You can disable building the local documentation with --no-ri and --no-rdoc, but there really shouldn’t be a problem with that step of a gem install. If you wait a few hours you can skip the whole “–pre” business altogether, as 3.0.0 will be released =) ---
**Author:** ![nobosh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/ecb155/32.png) [@nobosh](https://www.ruby-forum.com/u/nobosh)\ **Post date:** [August 30, 2010, 1:48am UTC](https://www.ruby-forum.com/t/updating-to-rails-3-on-mac-os-x/194080/5 "2010-08-30T01:48:38Z")
lol can’t wait. Your trick below worked. Thanks. I’m looking forward to upgrading in a few hours!