How to get Ruby / Homebrew / RVM to work on Yosemite?

After installing Yosemite, I was unable to run brew or ruby.

I was getting this error on brew update:

/usr/local/bin/brew: /usr/local/Library/brew.rb: /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby: bad interpreter: No such file or directory
/usr/local/bin/brew: line 23: /usr/local/Library/brew.rb: Undefined error: 0

getting this error on irb:

/System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/fileutils.rb:245:in mkdir': Permission denied - /Library/Ruby/Gems/2.0.0/extensions/universal-darwin-14 (Errno::EACCES) from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/fileutils.rb:245:infu_mkdir'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/fileutils.rb:219:in block (2 levels) in mkdir_p' from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/fileutils.rb:217:inreverse_each'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/fileutils.rb:217:in block in mkdir_p' from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/fileutils.rb:203:ineach'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/fileutils.rb:203:in mkdir_p' from /Library/Ruby/Site/2.0.0/rubygems/ext/builder.rb:210:inwrite_gem_make_out'
from /Library/Ruby/Site/2.0.0/rubygems/ext/builder.rb:132:in build_error' from /Library/Ruby/Site/2.0.0/rubygems/ext/builder.rb:171:inrescue in build_extension'
from /Library/Ruby/Site/2.0.0/rubygems/ext/builder.rb:156:in build_extension' from /Library/Ruby/Site/2.0.0/rubygems/ext/builder.rb:198:inblock in build_extensions'
from /Library/Ruby/Site/2.0.0/rubygems/ext/builder.rb:195:in each' from /Library/Ruby/Site/2.0.0/rubygems/ext/builder.rb:195:inbuild_extensions'
from /Library/Ruby/Site/2.0.0/rubygems/specification.rb:1436:in block in build_extensions' from /Library/Ruby/Site/2.0.0/rubygems/user_interaction.rb:45:inuse_ui'
from /Library/Ruby/Site/2.0.0/rubygems/specification.rb:1434:in build_extensions' from /Library/Ruby/Site/2.0.0/rubygems/stub_specification.rb:60:inbuild_extensions'
from /Library/Ruby/Site/2.0.0/rubygems/basic_specification.rb:56:in contains_requirable_file?' from /Library/Ruby/Site/2.0.0/rubygems/specification.rb:925:inblock in find_inactive_by_path'
from /Library/Ruby/Site/2.0.0/rubygems/specification.rb:924:in each' from /Library/Ruby/Site/2.0.0/rubygems/specification.rb:924:infind'
from /Library/Ruby/Site/2.0.0/rubygems/specification.rb:924:in find_inactive_by_path' from /Library/Ruby/Site/2.0.0/rubygems.rb:185:intry_activate'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/irb/locale.rb:150:in block in search_file' from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/irb/locale.rb:158:inblock in each_localized_path'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/irb/locale.rb:167:in each_sublocale' from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/irb/locale.rb:157:ineach_localized_path'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/irb/locale.rb:145:in search_file' from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/irb/locale.rb:124:infind'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/irb/locale.rb:108:in load' from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/irb/locale.rb:32:ininitialize'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/irb/init.rb:114:in new' from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/irb/init.rb:114:ininit_config'
from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/irb/init.rb:16:in setup' from /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/irb.rb:380:instart'
from /usr/bin/irb:12:in `'

This error can easily be fixed in the following steps:

1. Open terminal

2. Type nano /usr/local/Library/brew.rb

3. In the first line change “1.8″ to “Current”, so it should look like this:

   #!/System/Library/Frameworks/Ruby.framework/Versions/Current/usr/bin/ruby -W0

via http://blog.ic3man.gr/2014/06/homebrew-ruby-bad-interpreter-no-such-file-or-directory/

I updated to Yosemite and later found out brew was broken.

/usr/local/bin/brew: /usr/local/Library/brew.rb: 
/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby: bad interpreter: No such file or directory /usr/local/bin/brew: line 23: /usr/local/Library/brew.rb: Undefined error: 0

If you haven't made any changes to brew yet, here is what I recommend. Otherwise read further below.

1. cd /System/Library/Frameworks/Ruby.framework/Versions/
2. sudo ln -s Current 1.8
3. brew update
4. sudo unlink 1.8

Already made changes to brew files and stuck in a git mess?

I tried to edit /usr/local/Library/brew.rb but the local change to my git repo was preventing brew update from pulling down updates. I tried some other solutions mentioned on this page and from other sites and I ended up with a git mess and all I wanted to do was undo everything I had done to brew.

I committed my change but it made things worse. Eventually I had to undo my commits and git reset --hard HEAD~1 until I was at the right commit-ish. I had a mess of unversioned files too (I changed files permissions in /usr/Local) so I did a git clean -f -d which removed all unversioned files and directories and got me back to where I started before I made any changes.

Steps to fix it:

1. Install command line tools for Xcode 6

2. Reinstall brew:

    ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
   

3. Once brew is installed, rvm will work:

    rvm install ruby
   

Worked for me, yahoo!

Editing the script means brew update won't work; there are local edits to tracked files which causes the git pull to fail.

I did this, which I suspect is cleaner:

cd /usr/local/Library
git pull -q origin refs/heads/master:refs/remotes/origin/master

There are no complaints from brew doctor.

This is a conglomeration from answers from other people's posts as well as a bit of digging on Google, but I figured I'd put it up so a complete answer is in one place. Specifically this gets things to work now, but also lets you do brew updates as normal and gets everything clean again.

1. Open /usr/local/Library/brew.rb (emacs/vi/nano/whatever)
2. Change the first line to read: #!/System/Library/Frameworks/Ruby.framework/Versions/Current/usr/bin/ruby -W0. You're just changing the "1.8" that was in that line to "Current" (make sure you keep the capital "C" otherwise git will get confused later).
3. cd $(brew --repository)
4. git add Library/brew.rb
5. git commit -m "upgrading to ruby 2.0"
6. brew update (or sudo brew update if your brew is setup to only do system changes with sudo)

Credit: a lot of this came from here, though I really recommend against doing git commit -am in your /usr/local folder.

Like the one before said:

1. Change to current
2. install xcode 6

If you now have further problems with brew and ruby this should help: Somehow brew needs ruby on version 1.8, so create the folder:

sudo mkdir -p /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin

and make a symlink:

sudo ln -s /usr/bin/ruby /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby

Take a look at this tutorial here: http://ryantvenge.com/2014/09/ruby-homebrea-yosemite/

It worked for me!

I fixed this as follows：

1. sudo chown -R $(whoami):admin /usr/local
2. cd $(brew --prefix) && git fetch origin && git reset --hard origin/master

brew update error can be fixed with this:

sudo chown -R $USER:admin /usr/local
cd /usr/local
git reset --hard origin/master
brew update

https://github.com/Homebrew/homebrew/issues/19140

Note: Only do the below if you end up in a completely failed state, as this is very DANGEROUS

As an example I kept getting >$ sudo ln -s Current 1.8 > >$ brew update > >/usr/local/Library/brew.rb:18:in ': undefined method help?’ for [“update”]:Array (NoMethodError)

I just get this…(no matter what command just switch out “update” with the command) I solved the problem by asking for a buddies /usr/local folder. I then made a backup of my /usr/local folder.

>sudo mv /usr/local /usr/local.orig

I then moved his /usr/local to mine

>sudo mv ~/Downloads/local /usr/local

Note: You will likely lose some data so make sure to make a backup.

I had problems trying to install Ruby using package managers. In fairness to these programs, I admit to having little experience with them and did not make the effort to dig deeper as most of the other responders did. I'm lazy and prefer to use a binary installer available for most opsys choices and many packages. Unfortunately, Ruby doesn't seem to supply one.

I found ruby-build easy to install (stand alone - not the plugin), and it built Ruby from sources without error and placed it where I wanted it.

Bingo - easy:) This looks like a good alternative for those of us of the package manager challenged persuasion.

Charlie