Installing rmagick on osx 10.7.3 crashed - ruby-on-rails-3

Question

I got a problem to install rmagick on my osx 10.7.3 lion
I used rvm
Imagemagick is installed with homebrew
gem install rmagick
Fetching: rmagick-2.13.1.gem (100%)
Building native extensions. This could take a while...
ERROR: Error installing rmagick:
ERROR: Failed to build gem native extension
/Users/lion/.rvm/rubies/ruby-1.9.3-p0/bin/ruby extconf.rb
checking for Ruby version >= 1.8.5... yes
extconf.rb:128: Use RbConfig instead of obsolete and deprecated Config.
checking for clang... yes
checking for Magick-config... yes
checking for ImageMagick version >= 6.4.9... yes
checking for HDRI disabled version of ImageMagick... yes
checking for stdint.h... *** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers. Check the mkmf.log file for more
details. You may need configuration options.
Provided configuration options:
--with-opt-dir
--with-opt-include
--without-opt-include=${opt-dir}/include
--with-opt-lib
--without-opt-lib=${opt-dir}/lib
--with-make-prog
--without-make-prog
--srcdir=.
--curdir
--ruby=/Users/lion/.rvm/rubies/ruby-1.9.3-p0/bin/ruby
/Users/lion/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/mkmf.rb:381:in
try_do': The compiler failed to generate an executable file.
(RuntimeError)
You have to install development tools first.
from /Users/lion/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/mkmf.rb:506:in
try_cpp'
from /Users/lion/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/mkmf.rb:931:in
block in have_header'
from /Users/lion/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/mkmf.rb:790:in
block in checking_for'
from /Users/lion/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/mkmf.rb:284:in
block (2 levels) in postpone'
from /Users/lion/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/mkmf.rb:254:in
open'
from /Users/lion/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/mkmf.rb:284:in
block in postpone'
from /Users/lion/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/mkmf.rb:254:in
open'
from /Users/lion/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/mkmf.rb:280:in
postpone'
from /Users/lion/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/mkmf.rb:789:in
checking_for'
from /Users/lion/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/mkmf.rb:930:in
have_header'
from extconf.rb:193:in'
Gem files will remain installed in /Users/lion/.rvm/gems/ruby-1.9.3-p0/gems/rmagick-2.13.1 for
inspection.
Results logged to /Users/lion/.rvm/gems/ruby-1.9.3-p0/gems/rmagick-2.13.1/ext/RMagick/gem_make.out
Did anyone know what i can do to install rmagick correctly?

Answer 1

I'm going to take a guess that it's an upgrade and not pre-installed? I recently upgraded to Lion and had to do something like:
uninstall xcode 3 (there's a non-destructive version of the uninstall script in case you care)
install xcode 4 (free from the app store. big download).
i use macports. i had to uninstall and reinstall them all. you'll need to do the same for homebrew if you haven't already.
symlink or pass on command line the new gcc compiler (rmagick references gcc-4.2, but with xcode 4 it's called llvm-gcc-4.2. look up what that means if you're interested http://llvm.org/)
That pretty much sums up what I had to do. The clue was in the mkmf.log, so definitely look in there and update your question if my answer doesn't do it for you.