Estoy tratando de instalar ruby-oci8 en OS X.

He intentado instalar tanto con como sinsudo.

Mensaje de error sinsudo:

gem install ruby-oci8
ERROR:  While executing gem ... (Gem::FilePermissionError)
    You don't have write permissions into the /Library/Ruby/Gems/1.8 directory.

Mensaje de error consudo:

sudo gem install ruby-oci8
Password:
Building native extensions.  This could take a while...
ERROR:  Error installing ruby-oci8:
    ERROR: Failed to build gem native extension.

        /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby extconf.rb
checking for load library path... 
  DYLD_LIBRARY_PATH is not set.
checking for cc... ok
checking for gcc... yes
checking for LP64... yes
checking for sys/types.h... yes
checking for ruby header... ok
*** 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=/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby
    --with-instant-client
    --without-instant-client
./oraconf.rb:887:in `get_home': RuntimeError (RuntimeError)
    from ./oraconf.rb:703:in `initialize'
    from ./oraconf.rb:319:in `new'
    from ./oraconf.rb:319:in `get'
    from extconf.rb:18

Mensaje de error:

Set the environment variable ORACLE_HOME if Oracle Full Client.
Append the path of Oracle client libraries to DYLD_LIBRARY_PATH if Oracle Instant Client.

The 'sudo' command unset some environment variables for security reasons.
Pass required varialbes as follows
     sudo env DYLD_LIBRARY_PATH=$DYLD_LIBRARY_PATH /usr/bin/gem install ruby-oci8
  or 
     sudo env ORACLE_HOME=$ORACLE_HOME /usr/bin/gem install ruby-oci8


Backtrace:
  ./oraconf.rb:887:in `get_home'
  ./oraconf.rb:703:in `initialize'
  ./oraconf.rb:319:in `new'
  ./oraconf.rb:319:in `get'
  extconf.rb:18

See:
 * http://ruby-oci8.rubyforge.org/en/HowToInstall.html
 * http://ruby-oci8.rubyforge.org/en/ReportInstallProblem.html