rmagick gem installed on windows but bundle fails - ruby-on-rails

Question

From a Rails and Bundler newbie.
I was able to install rmagick 2.13.2 on MS Windows 7 with:
gem install rmagick -v 2.13.2 -- --with-opt-lib=c:/ImageMagick/lib --with-opt-include=c:/ImageMagick/include --local
Which worked, shown in this output:
Temporarily enhancing PATH to include DevKit...
Building native extensions. This could take a while...
Successfully installed rmagick-2.13.2
1 gem installed
Installing ri documentation for rmagick-2.13.2...
Installing RDoc documentation for rmagick-2.13.2...
But I can't get bundler to use my gemfile, which contains the line:
gem "rmagick"
But the command:
bundle install --path vendor/bundle/
faults on rmagick like this:
Installing rmagick (2.13.2)
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension
.
C:/RailsInstaller/Ruby1.9.3/bin/ruby.exe extconf.rb
checking for Ruby version >= 1.8.5... 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
--without-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=C:/RailsInstaller/Ruby1.9.3/bin/ruby
C:/RailsInstaller/Ruby1.9.3/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 C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/mkmf.rb:506:in `try_cpp'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/mkmf.rb:931:in `block in
have_header'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/mkmf.rb:790:in `block in
checking_for'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/mkmf.rb:284:in `block (2
levels) in postpone'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/mkmf.rb:254:in `open'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/mkmf.rb:284:in `block in
postpone'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/mkmf.rb:254:in `open'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/mkmf.rb:280:in `postpone
'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/mkmf.rb:789:in `checking
_for'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/mkmf.rb:930:in `have_hea
der'
from extconf.rb:194:in `<main>'
Gem files will remain installed in c:/ew/j2ee/axxon.dash/vendor/bundle/ruby/1.9.
1/gems/rmagick-2.13.2 for inspection.
Results logged to c:/ew/j2ee/axxon.dash/vendor/bundle/ruby/1.9.1/gems/rmagick-2.
13.2/ext/RMagick/gem_make.out
An error occurred while installing rmagick (2.13.2), and Bundler cannot
continue.
Make sure that `gem install rmagick -v '2.13.2'` succeeds before bundling.
Also,
>gem list rmagick
*** LOCAL GEMS ***
rmagick (2.13.2)
I checked and rmagic seems to be installed in vendor\bundle\ruby\1.9.1\gems\rmagick-2.13.2
So if it's installed, why is bundle install complaining?
Can I cheat bundler and force it to recognize what I've done or something?
TIA.

Answer 1

you should define rmagick gem like this :
gem 'rmagick', '~> 2.13.2', :platforms => :ruby
gem 'rmagick', '=2.13.2.mswin32', :platforms => :mswin
Hope this will help.