Installing rvm on a Mac - Issues With gcc

While installing RVM on a mac, one of the major problems we face are due to missing Xcode. We usually get the error below:

    rvm install 1.9.3
    Installing Ruby from source to: /Users/jamie/.rvm/rubies/ruby-1.9.3-p0, this may take a while depending on your cpu(s)...

    ruby-1.9.3-p0 - #fetching 
    ruby-1.9.3-p0 - #extracted to /Users/jamie/.rvm/src/ruby-1.9.3-p0 (already extracted)
    Fetching yaml-0.1.4.tar.gz to /Users/jamie/.rvm/archives
    Extracting yaml-0.1.4.tar.gz to /Users/jamie/.rvm/src
    Configuring yaml in /Users/jamie/.rvm/src/yaml-0.1.4.
    Compiling yaml in /Users/jamie/.rvm/src/yaml-0.1.4.
    Installing yaml to /Users/jamie/.rvm/usr
    ruby-1.9.3-p0 - #configuring 
    ERROR: Error running ' ./configure --prefix=/Users/jamie/.rvm/rubies/ruby-1.9.3-p0 --enable-shared --disable-install-doc --with-libyaml-dir=/Users/jamie/.rvm/usr ', please read /Users/jamie/.rvm/log/ruby-1.9.3-p0/configure.log
    ERROR: There has been an error while running configure. Halting the installation.

The Error message also looks like this:

rvm install 1.9.3
ERROR: The autodetected CC(/usr/bin/gcc-4.2) is LLVM based, it is not yet fully supported by ruby and gems, please read `rvm requirements`, and set CC=/path/to/gcc .

Find the GCC installed in Mac:

gcc -v
Using built-in specs.
Target: i686-apple-darwin11
Configured with: /private/var/tmp/llvmgcc42/llvmgcc42-2336.1~1/src/configure --disable-checking --enable-werror --prefix=/Developer/usr/llvm-gcc-4.2 --mandir=/share/man --enable-languages=c,objc,c++,obj-c++ --program-prefix=llvm- --program-transform-name=/^[cg][^.-]*$/s/$/-4.2/ --with-slibdir=/usr/lib --build=i686-apple-darwin11 --enable-llvm=/private/var/tmp/llvmgcc42/llvmgcc42-2336.1~1/dst-llvmCore/Developer/usr/local --program-prefix=i686-apple-darwin11- --host=x86_64-apple-darwin11 --target=i686-apple-darwin11 --with-gxx-include-dir=/usr/include/c++/4.2.1
Thread model: posix
gcc version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.1.00)

also look for the files in user/bin

ls /usr/bin | grep gcc

Here are a few ways to resolve this - read them all to get a better understanding of ways to fix issues like these:

  • Install with clang
rvm install 1.9.3 --with-gcc=clang
  • Install a lighter version of gcc osx-gcc


Be carefull about this, sometimes there are conflicts with Brew

  • The best of them all could still be to use the command line tools for xcode

  • If you face issues with readline, its best to pkg install readline

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


Any questions on this, please feel free to ask. We’re here to help…