Issue updating Ruby on Mac with Xcode 4.3.1

Question

I'm using RVM to install it and it gives me this error:

The provided compiler '/usr/bin/gcc' is LLVM based, it is not yet fully supported by ruby and gems, please read `rvm requirements`.

I'm on Lion 10.7.3 and I have Xcode 4.3.1.

Answer 1

Short answer is you can grab RVM master branch (not stable) to build it with LLVM (not gcc, I mistyped initially). It has appropriate patches to make 1.9.3-p125 to run (at least better) with Xcode 4.3.1 by default. I provided the patch. If you already installed RVM, rvm get head will install the master branch. With command line tools installed with Xcode 4.3.1, you can successfully install Ruby 1.9.3-p125.

Background

It's happen due to a simple configuration issue of Ruby 1.9.3-p125, it don't allow dynamic link modules to work. This happens if you're using Xcode 4.3.x (Ruby Issue#6080).

This issue have fixed in change set r34840.

RVM has patch system which provides per-version basis. This patch is included in the RVM (master branch for now) and now default for p125 configuration steps.

Xcode 4.3.x Command Line Tool

First, With Xcode 4.3.x, you need to install command line tool AFTER installing Xcode 4.3.x, by following directions: 1) Launching Xcode, 2) Open “Preferences” from the “Xcode” item on the menu bar. 3) Select “Downloads” tab (icon). 4) Click “Install” button for “Command Line Tools” (directions borrowed from my friend's site here)

If Xcode 4.3.1 is correctly installed, then cc --version should emit:

% cc --version
Apple clang version 3.1 (tags/Apple/clang-318.0.54) (based on LLVM 3.1svn)
Target: x86_64-apple-darwin11.3.0
Thread model: posix

autoconf and automake

You need autoconf and automake, since Xcode 4.3.x don't have them. Install them either brew or MacPorts. With MacPorts:

sudo port install autoconf automake

Recommended installation step with RVM

Then, To install specific branch of RVM, you can:

REPO=wayneeseguin
BRANCH=master # stable for the stable branch
curl -s https://raw.github.com/${REPO}/rvm/${BRANCH}/binscripts/rvm-installer > /tmp/rvm-installer.sh
bash /tmp/rvm-installer.sh --branch ${REPO}/${BRANCH}

Or if RVM is already installed:

rvm get head   # master branch, for stable branch "rvm get stable"

After that, install openssl, iconv and readline using rvm pkg command for best result. I do following lately. Part of this might need to be included to RVM..

rvm pkg install openssl
rvm pkg install readline # if you prefer GNU readline

Then, finally, install the Ruby.

rvm install 1.9.3-p125 --patch xcode-debugopt-fix-r34840.diff --with-readline-dir=$rvm_path/usr --with-openssl-dir=$rvm_path/usr --with-tcl-lib=/usr --with-tk-lib=/usr

rvm pkg's help recommend different parameter, the help is broken. So use above for now. You need tcl/tk parameters if you have them via MacPorts(like me)

By the way, It is possible to install old Xcode then run rvm with export CC="gcc-4.2" rvm install 1.9.3-p125, but I personally think clang (LLVM) is the way to go for future, if possible.

Hope this helps.

Additional note on 2012/3/31

iconv don't need to install, also added autoconf/automake requirements for clarifications.

Additional note on 2012/4/13

Latest stable does not include the patch require dynamic link to work by default. you need to add --patch xcode-debugopt-fix-r34840.diff when you build 1.9.3-p125.

Answer 2

As of RVM 1.10.2 all you need is to install the homebrew package apple-gcc42 and everything will "Just Work(TM)":

brew tap homebrew/dupes ; brew install apple-gcc42 ; rvm install ruby-1.9.2

Ciao!

[Updated based on comments below]