gem install fails

[aresnick]

Using Mac OS X 10.7.1, ruby 1.9.2p136 (2010-12-25 revision 30365) [x86_64-darwin10.6.0], and rubygems 1.6.2:

Fetching: ruby-filemagic-0.4.2.gem (100%)
Building native extensions.  This could take a while...
ERROR:  Error installing ruby-filemagic:
    ERROR: Failed to build gem native extension.

        /usr/local/Cellar/ruby/1.9.2-p136/bin/ruby extconf.rb
checking for magic_open() in -lmagic... no
*** ERROR: missing required library to compile this module
*** 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=/usr/local/Cellar/ruby/1.9.2-p136/bin/ruby
    --with-magic-dir
    --without-magic-dir
    --with-magic-include
    --without-magic-include=${magic-dir}/include
    --with-magic-lib
    --without-magic-lib=${magic-dir}/lib
    --with-magiclib
    --without-magiclib

Gem files will remain installed in /Users/aresnick/.rvm/gems/ruby-1.9.2-p180/gems/ruby-filemagic-0.4.2 for inspection.
Results logged to /Users/aresnick/.rvm/gems/ruby-1.9.2-p180/gems/ruby-filemagic-0.4.2/ext/gem_make.out

[blackwinter]

checking for magic_open() in -lmagic... no

please make sure you have the header files for libmagic installed.