Question

I’m new to Terminal so please bear with me. Completed installing the following successfully (in this particular order):

• xCode 4.5
• RVM 1.16
• GCC 4.2.1
• Ruby 1.9.3

When trying to install Rails (“gem install rails”) the installation starts but is then interrupted with an error: “Failed to build gem native extension”. No idea what this refers to. Ideas? Something else I need to install beforehand?
On my first attempt to install Rails I accidentally ran it with sudo. Will this affect anything?

Edit: And the output –

Building native extensions.  This could take a while...
ERROR:  Error installing rails:
    ERROR: Failed to build gem native extension.

        /Users/staffanestberg/.rvm/rubies/ruby-1.9.3-p194/bin/ruby extconf.rb
creating Makefile

make
compiling generator.c
make: /usr/bin/gcc-4.2: No such file or directory
make: *** [generator.o] Error 1

Gem files will remain installed in /Users/staffanestberg/.rvm/gems/ruby-1.9.3-p194/gems/json-1.7.5 for inspection.
Results logged to /Users/staffanestberg/.rvm/gems/ruby-1.9.3-p194/gems/json-1.7.5/ext/json/ext/generator/gem_make.out

Edit: Solved using iouri’s suggestion. Add export CC=gcc in .bash-profile then create a symlink for the correct compiler,

sudo ln -sf /usr/bin/llvm-gcc-4.2 /usr/bin/gcc-4.2

Answer 1

Make sure you have command line tools for Xcode installed first, Xcode > Preferences > Downloads > Components. Then add this line to your .bash_profile file in your home folder ~/.bash_profile:

export CC=gcc

Double check that you have gcc (probably a symlink) in your /usr/bin (most likely), and that it is pointing to a valid gcc compiler, ex: gcc -> llvm-gcc-4.2

You might have to restart your terminal for this change to take affect.