Can't install Ruby under Lion with RVM – GCC issues

Question

This answer was edited multiple times and now contains several alternative solutions. Try the simple “Edit 3” solution first.

Ruby 1.9.3-p125 and later have official support for clang, so if you are installing such a version you should not need GCC. If you’re installing an older version of Ruby, read on.

To compile Ruby with GCC, you need a non-LLVM version of GCC, which is no longer included with Xcode 4.2. Install it yourself (or downgrade to Xcode 4.1 temporarily), then do CC=/usr/local/bin/gcc-4.2 rvm install 1.9.3 --enable-shared (substituting the path to your non-LLVM gcc).

Edit: https://github.com/kennethreitz/osx-gcc-installer/downloads may help for installing GCC. There is also some info available by running rvm requirements.

Edit 2: For an easier solution, you can try adding --with-gcc=clang to the arguments to configure for Ruby to use clang instead of GCC.

Edit 3: rvm install 1.9.3 --with-gcc=clang does that for you.

Note: With current versions of Xcode you need to install the command-line tools separately from the Xcode menu -> Preferences -> Downloads -> Components. This is a pre-requisite for doing any compiling with Xcode on the command-line, not just Ruby.

Note 2: If something doesn't work after following the steps, try doing a reboot or re-login to ensure that the environment gets set correctly.

Note 3: Ruby versions prior to 1.9.3-p125 may not always be fully compatible with clang, so test your software thoroughly if using the “edit 3” solution in a production environment.

SUMMARY FOR STACK OVERFLOW

I was trying to install SiriProxy on a clean Lion installation on Xcode from App Store

I kept getting errors like : The provided CC(/usr/bin/gcc) is LLVM based.

bash-3.2$ rvm install 1.9.3
ERROR: The provided CC(/usr/bin/gcc) is LLVM based, it is not yet fully supported by ruby and gems, please read `rvm requirements`.

After 2 days finally got it working with these two lines:

http://stackoverflow.com/questions/8000145/ruby-rvm-llvm-and-mysql

bash-3.2$ rvm get head
bash-3.2$ CC=/usr/bin/gcc-4.2 rvm install 1.9.3 --enable-shared

Before that I had tried every stackoverflow article on Ruby and Lion so doing these may have done some setup that helped the above 2 steps work:

Things I tried included:

Running Install Xcode.app (I had downloaded from App Store - running this does futher installation)

Installing

https://github.com/kennethreitz/osx-gcc-installer/downloads may help for installing GCC.

Set up CC in

more /Users//.bash_profile

bash-3.2$ more /Users/<USERNAME>/.bash_profile 
[[ -s "$HOME/.rvm/scripts/rvm" ]] && . "$HOME/.rvm/scripts/rvm" # Load RVM function
export CC=/usr/share/TargetConfigs/bin/gcc

First line came from SiriProxy install instruction https://github.com/plamoni/SiriProxy

2nd line export CC never seemed to work. So dont add.

It had many versions each pointing I finally used CC=/usr/bin/gcc-4.2 rvm install 1.9.3 --enable-shared

rvm install 1.9.3 --with-gcc=clang

Worked for me. This was on a brand new Lion with Xcode (had no "traditional" GCC).

OK I didn't have to install gcc-4.2 separately, I used the one delivered in Xcode, but I had an issue where the --with-gcc=clang wasn't getting passed through. Added the following line to my .rvmrc:

export rvm_configure_flags="--with-gcc=clang"

Worked as required

rvm upgrade ruby-1.9.2-p290 ruby-1.9.3-p125
...
ruby-1.9.3-p125 - #extracted to /Users/leif/.rvm/src/ruby-1.9.3-p125 (already extracted)
ruby-1.9.3-p125 - #configuring
ruby-1.9.3-p125 - #compiling 
ruby-1.9.3-p125 - #installing
....
Successfully migrated ruby-1.9.2-p290 to ruby-1.9.3-p125
Upgrade complete!

bang:$ ruby -v
ruby 1.9.3p125 (2012-02-16 revision 34643) [x86_64-darwin11.3.0]

Note my env is the following

OS

Darwin bang.local 11.3.0 Darwin Kernel Version 11.3.0: Thu Jan 12 18:47:41 PST 2012; root:xnu-1699.24.23~1/RELEASE_X86_64 x86_64

Xcode

Xcode 4.2.1 Build 4D502

GCC

i686-apple-darwin11-llvm-gcc-4.2 (GCC) 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.1.00)

lrwxr-xr-x  1 root  wheel  12 22 Dec 21:30 /usr/bin/gcc -> llvm-gcc-4.2

I tried using the answer of passing --with-gcc=clang on the command line to the rvm upgrade command, but it didn't work, it didn't appear to get pass from rvm to configure. Apparently the problem in RVM of arguments not being passed to configure is fixed (in commit 1641ceb0 in 2011), but even after upgrading RVM to latest (via rvm get latest) it still didn't get passed. Using the .rvmrc file was the only way it would work for me.

Only answering here because I can can't up vote/comment on leandro's comment on the original question. After spending days trying to get this to work, His solution was the one that finally got it working for me:

edit3 didn'work for me (Xcode 4.2.1), but after installing readline

 rvm pkg install readline 

and passing an extra parameter

rvm install 1.9.3 --with-gcc=clang --with-readline-dir=$rvm_path/usr 

it installed successfully.

You can try to install Command Line Tools for Xcode, it includes GCC, LLMV and other tools that excluded in Xcode 4.2 and higher.