Seems like I should post my famous 5 lines again:

1. Install XCode and homebrew

2. sudo brew install {postgresql,rbenv,ruby-build}

3. Close terminal. Open terminal.

4. mkdir proj && cd proj && rbenv install 1.9.2-p290 && rbenv local 1.9.2-p290

5. gem install rails && rbenv rehash

6. rails new foo

That should get you up and running on any OSX with a sustainable environment (i.e. one that you can actually reproduce in the future and that can mimic your live servers).

> sudo brew install

No sudo. From https://github.com/mxcl/homebrew/wiki/FAQ:

> Why does Homebrew say sudo is bad? > tl;dr Sudo is dangerous, and you installed TextMate.app without sudo anyway.

> Homebrew is designed to work without using sudo. You can decide to use it but we strongly recommend not to do so. If you have used sudo and run into a bug then it is likely to be the cause. Please don’t file a bug report unless you can reproduce it after reinstalling Homebrew from scratch without using sudo.

This is correct, but replace 1.9.2-p290 with 1.9.3-p125.

Plus falcon patches? Here's a ruby-build formula for that:

    $ cat share/ruby-build/1.9.3-p125-falcon
    ## Hat tip to @burkelibbey and @metaskills - who did all the real work
    
    build_package_combined_patch() {
      local package_name="$1"
    
      {
        curl https://github.com/ruby/ruby/pull/47.diff | git apply
        curl https://raw.github.com/gist/1859082/performance_and_backport_gc.patch | patch -p1
        autoconf
        ./configure --prefix="$PREFIX_PATH" $CONFIGURE_OPTS
        make -j 8
        make install
      } >&4 2>&1
    
    }
    
    CC=$(which clang) install_package "yaml-0.1.4" "http://pyyaml.org/download/libyaml/yaml-0.1.4.tar.gz"
    CC=$(which clang) install_package "ruby-1.9.3-p125" "http://ftp.ruby-lang.org/pub/ruby/1.9/ruby-1.9.3-p125.tar.gz" combined_patch

There's this gist which combines all the patches and has you install a 1.9.3-p125-perf via rbenv: https://gist.github.com/2113359

Been using it at work for local dev and in production. Feels good, man.

Thanks!

When I returned to Rails after a couple of years away from it, I had to piece together a few different blog posts about setting up Rails 3 with Ruby 1.9 on Mac OS X to get my toolchain working, and even then I had to troubleshoot version-specific problems not covered in the blogs. I believe most beginners would have been deterred from continuing. I don't really use Rails on Windows much at all, but tried RailsInstaller on Windows 7 just for fun about a year ago and was delighted it worked so well and would like for beginners to have such an easy experience on a Mac, my OS of choice!

It's not. At the very least, you'll want to upgrade to a 1.9 version of Ruby - even in 10.7, I'm pretty sure it still comes out of the box with 1.8.7.

Also, most of the Ruby or Rails developers I know use either rvm or rbenv to have multiple versions of Ruby installed side by side.

I run Rails 3.2.3 with Ruby 1.8.7 on Snow Leopard without problems :)

Right, and that's the last release series that will support 1.8.7. Thus, you'll want Ruby 1.9 eventually. Besides Rails compatibility, 1.9 is faster, includes lots of nice new syntaxes and methods for doing things, better encoding support, etc.

Also, 1.8.7 EOL is so close that you should not choose it for new projects.

My MacBook EOL is also very close, I'm waiting for the new Apple hardware releas. I'll switch them both together : Christmas waaaaay before Christmas.

This is targeted at beginners with little/no programming experience.

cool