Trouble downgrading Ruby on OS X Mavericks

Question

OS X 10.9 comes with ruby 2.0.0p195 but I need to install Ruby 1.8.7. I keep running into errors. I have Xcode5-DP install and I believe Command Line Tools is installed too.

In the terminal:

sudo rvm install 1.8.7
Searching for binary rubies, this might take some time.
No binary rubies available for: osx/10/x86_64/ruby-1.8.7-p371.
Continuing with compilation. Please read 'rvm mount' to get more information on binary rubies.
Installing requirements for osx, might require sudo password.
Certificates in '/usr/local/etc/openssl/cert.pem' already are up to date.
Installing Ruby from source to: /Users/alextoul/.rvm/rubies/ruby-1.8.7-p371, this may take a while depending on your cpu(s)...
ruby-1.8.7-p371 - #downloading ruby-1.8.7-p371, this may take a while depending on your connection...
ruby-1.8.7-p371 - #extracted to /Users/alextoul/.rvm/src/ruby-1.8.7-p371 (already extracted)
Patch stdout-rouge-fix was already applied.
Patch no_sslv2 was already applied.
ruby-1.8.7-p371 - #configuring...
Error running 'env CFLAGS=-O3 -I/usr/local/opt/libyaml/include -I/usr/local/opt/readline/include -I/usr/local/opt/libxml2/include -I/usr/local/opt/libxslt/include -I/usr/local/opt/libksba/include -I/usr/local/opt/openssl098/include LDFLAGS=-L/usr/local/opt/libyaml/lib -L/usr/local/opt/readline/lib -L/usr/local/opt/libxml2/lib -L/usr/local/opt/libxslt/lib -L/usr/local/opt/libksba/lib -L/usr/local/opt/openssl098/lib ./configure --prefix=/Users/alextoul/.rvm/rubies/ruby-1.8.7-p371 --disable-install-doc --without-tcl --without-tk --enable-shared',
please read /Users/alextoul/.rvm/log/ruby-1.8.7-p371/1371228839_configure.log
There has been an error while running configure. Halting the installation.

1371228839_configure.log says:

./configure
configure: WARNING: unrecognized options: --without-tcl, --without-tk
checking build system type... i686-apple-darwin13.0.0
checking host system type... i686-apple-darwin13.0.0
checking target system type... i686-apple-darwin13.0.0
checking whether the C compiler works... no
configure: error: in `/Users/alextoul/.rvm/src/ruby-1.8.7-p371':
configure: error: C compiler cannot create executables
See `config.log' for more details

Other (useful) info:

ruby -v
> ruby 2.0.0p195 (2013-05-14 revision 40734) [universal.x86_64-darwin13]
brew update
> Already up-to-date.
gcc --version
> Configured with: --prefix=/Applications/Xcode5-DP.app/Contents/Developer/usr --with-gxx-include-dir=/Applications/Xcode5-DP.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/include/c++/4.2.1
> Apple LLVM version 5.0 (clang-500.1.58) (based on LLVM 3.3svn)
> Target: x86_64-apple-darwin13.0.0
> Thread model: posix
sudo rvm requirements
> Installing requirements for osx, might require sudo password.
> Certificates in '/usr/local/etc/openssl/cert.pem' already are up to date.

Thanks for your help.

Answer 1

10.9 is an early beta build of the OS. [Edit: please note the July 2013 date of this answer] If I were running 10.9 I would assume I'll have to reinstall the operating system from scratch at least 2 more times. (At least once during the beta cycle because, well, it's beta, and once when 10.9 comes out in general release, because, well, beta).

Given this I suggest four courses of action (pick 1 or many):

• Work with the RVM guys and dig into 10.9's probably-changed compiler environment and get Ruby 1.8.7 compiling. This is trickier because technically this stuff is under NDA.
• Instead, set up a VM and run Ruby 1.8.7 on the VM. Bonus points for using Vagrant and Chef/Puppet, because you may even need to rebuild the VM. (Just keep the Vagrantfile and Puppet or Chef config files on Github/Dropbox/whatever so you can clone them and regenerate your VM from scratch.)
• OR simply reboot to 10.8 to get production work done. 10.8 is a production level OS, 10.9 should be treated with caution - it could eat your work. It really shouldn't be used for production purposes (aka: day to day writing Ruby code). If you're writing a 10.9 only app in Cocoa/Objective-C (or updating RubyMotion or something) that might be another thing (but I'd still keep good backups and treat it gently).
• Work towards updating your code base for Ruby 2.0, as Ruby 1.8.7 is no longer officially supported anyway.

Edit (Oct 24, 2013): If you're here because you just installed Mavericks (released Oct 22, 2013), want to get Ruby 1.8.7 working a few days after this release, and RVM isn't working for you (because you're impatient and can't wait), here's what you can do (which should work, although I'm not an rbenv user):

1. Use macports to install port install ruby. This is Ruby 1.8.7. This compilation worked for me on my Mavericks machine (although you will need to install Macports from source at this writing and install the command line developer tools, even if you have XCode 5 installed. Yes, really).
2. Now, install rbenv.
3. Symlink /opt/local/bin/ruby1.8 in the ~/.rbenv/versions/ folder. Specifically ~/.rbenv/versions/ruby-1.8.7-p374
4. Read the rbenv documentation, but it should work now! (At least from the documentation. Again, not an rbenv user, but do play one on TV)

I'm sure you can do this with homebrew too, but I know Ruby 1.8.7 installs correctly with the latest Macports, because that's what I use (and it just installed cleanly for me).

Answer 2

When you see this error message:

configure: error: C compiler cannot create executables:

First of all, make sure you have upgraded your commandline tools:

$ xcode-select --install

Now Apple wants you to agree to their license before you can use these tools:

$ gcc
Agreeing to the Xcode/iOS license requires admin privileges, please re-run as root via sudo.

$ sudo gcc
You have not agreed to the Xcode license agreements. You must agree to both license agreements below in order to use Xcode.
[...]

After you have accepted it, the commandline tools will work as expected.

Answer 3

If you've installed developer tools on OS X Mavericks Ruby 1.8 is already installed along with 2.0. So all you need to do is switch the 'Current' symbolic link to point to the 1.8 directory.

#Install Xcode Developer tools
xcode-select --install

#Delete Current symbolic link to Ruby 2.0
sudo rm /System/Library/Frameworks/Ruby.framework/Versions/Current

#Create new Current symbolic link to Ruby 1.8
sudo ln -s /System/Library/Frameworks/Ruby.framework/Versions/1.8 /System/Library/Frameworks/Ruby.framework/Versions/Current

#Check Ruby version is 1.8.7
ruby -v

Answer 4

Try this (ensure the dev toolchain is reachable):

$ sudo xcode-select -s /Applications/Xcode5-DP.app/Contents/Developer

Then retry.