Upgrade auf Lion, gem native Erweiterungen können nicht erstellt werden

Question

Ich bin mir nicht sicher, ob mein Problem mit diesem Thread (http://stackoverflow.com/questions/6589066/rmagick-and-os-x-lion) zusammenhängt, aber ich habe gerade auf Lion aktualisiert; genauer gesagt habe ich einen neuen Rechner gekauft und mein altes Profil migriert.

Ich kann Rails 3 nicht starten, weil es rmagick nicht finden kann, und ich kann rmagick nicht installieren, weil ich die folgende Fehlermeldung erhalte. Ich habe versucht, rmagick und imageMagick zu deinstallieren, aber ich erhalte immer noch den gleichen Fehler, wenn ich versuche, die Installation zu bündeln. Irgendwelche Ideen? Ich danke Ihnen

Installing rmagick (2.13.1) with native extensions /opt/local/lib/ruby/site_ruby/1.8/rubygems/installer.rb:551:in `build_extensions': ERROR:     Failed to build gem native extension. (Gem::Installer::ExtensionBuildError)

    /opt/local/bin/ruby extconf.rb 
checking for Ruby version >= 1.8.5... yes
checking for /usr/bin/gcc-4.2... no
No C compiler found in ${ENV['PATH']}. See mkmf.log for details.
*** 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=/opt/local/bin/ruby

Gem files will remain installed in /opt/local/lib/ruby/gems/1.8/gems/rmagick-2.13.1 for inspection.
Results logged to /opt/local/lib/ruby/gems/1.8/gems/rmagick-2.13.1/ext/RMagick/gem_make.out
from /opt/local/lib/ruby/site_ruby/1.8/rubygems/installer.rb:504:in `each'
from /opt/local/lib/ruby/site_ruby/1.8/rubygems/installer.rb:504:in `build_extensions'
from /opt/local/lib/ruby/site_ruby/1.8/rubygems/installer.rb:180:in `install'
from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.15/lib/bundler/source.rb:101:in `install'
from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.15/lib/bundler/rubygems_integration.rb:78:in `preserve_paths'
from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.15/lib/bundler/source.rb:91:in `install'
from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.15/lib/bundler/installer.rb:58:in `run'
from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.15/lib/bundler/rubygems_integration.rb:93:in `with_build_args'
from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.15/lib/bundler/installer.rb:57:in `run'
from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.15/lib/bundler/spec_set.rb:12:in `each'
from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.15/lib/bundler/spec_set.rb:12:in `each'
from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.15/lib/bundler/installer.rb:49:in `run'
from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.15/lib/bundler/installer.rb:8:in `install'
from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.15/lib/bundler/cli.rb:222:in `install'
from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.15/lib/bundler/vendor/thor/task.rb:22:in `send'
from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.15/lib/bundler/vendor/thor/task.rb:22:in `run'
from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.15/lib/bundler/vendor/thor/invocation.rb:118:in `invoke_task'
from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.15/lib/bundler/vendor/thor.rb:246:in `dispatch'
from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.15/lib/bundler/vendor/thor/base.rb:389:in `start'
from /opt/local/lib/ruby/gems/1.8/gems/bundler-1.0.15/bin/bundle:13
from /opt/local/bin/bundle:19:in `load'
from /opt/local/bin/bundle:19

UPDATE Ich habe also auf Xcode4 aktualisiert und als ich brew --config zeigt es immer noch an, dass ich GCC-Zeug vermisse:

HOMEBREW_VERSION: 0.8
HEAD: 8368fe489bde47b8f201bfcfdf328944fdf7092b
HOMEBREW_PREFIX: /usr/local
HOMEBREW_CELLAR: /usr/local/Cellar
HOMEBREW_REPOSITORY: /usr/local
HOMEBREW_LIBRARY_PATH: /usr/local/Library/Homebrew
Hardware: quad-core 64-bit sandybridge
OS X: 10.7
Kernel Architecture: x86_64
Ruby: 1.8.7-249
/usr/bin/ruby => /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby
Xcode: 
GCC-4.0: N/A 
GCC-4.2: N/A 

Wie kann das sein?