Po zainstalowaniu wersji demonstracyjnej OSX Mavericks 10.9, otrzymuję to po uruchomieniu pakietu

    Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.

    /Users/sandric/.rvm/rubies/ruby-1.9.3-p194/bin/ruby extconf.rb 
extconf.rb:17: Use RbConfig instead of obsolete and deprecated Config.
checking for socket() in -lsocket... *** 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=/Users/sandric/.rvm/rubies/ruby-1.9.3-p194/bin/ruby
    --with-iconv-dir
    --without-iconv-dir
    --with-iconv-include
    --without-iconv-include=${iconv-dir}/include
    --with-iconv-lib
    --without-iconv-lib=${iconv-dir}/lib
    --with-zlib-dir
    --without-zlib-dir
    --with-zlib-include
    --without-zlib-include=${zlib-dir}/include
    --with-zlib-lib
    --without-zlib-lib=${zlib-dir}/lib
    --with-socketlib
    --without-socketlib
/Users/sandric/.rvm/rubies/ruby-1.9.3-p194/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/sandric/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:461:in `try_link0'
    from /Users/sandric/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:476:in `try_link'
    from /Users/sandric/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:619:in `try_func'
    from /Users/sandric/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:845:in `block in have_library'
    from /Users/sandric/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:790:in `block in checking_for'
    from /Users/sandric/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:284:in `block (2 levels) in postpone'
    from /Users/sandric/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:254:in `open'
    from /Users/sandric/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:284:in `block in postpone'
    from /Users/sandric/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:254:in `open'
    from /Users/sandric/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:280:in `postpone'
    from /Users/sandric/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:789:in `checking_for'
    from /Users/sandric/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/mkmf.rb:840:in `have_library'
    from extconf.rb:27:in `<main>'


Gem files will remain installed in /Users/sandric/.bundler/tmp/5282/gems/libxml-ruby-2.6.0 for inspection.
Results logged to /Users/sandric/.bundler/tmp/5282/gems/libxml-ruby-2.6.0/ext/libxml/gem_make.out
An error occurred while installing libxml-ruby (2.6.0), and Bundler cannot continue.
Make sure that `gem install libxml-ruby -v '2.6.0'` succeeds before bundling.

Myślę, że nie mam narzędzi wiersza poleceń, więc próbowałem je pobrać. Okazało się, że nie ma zwykłego linku do tego w moim XCode (jest to 4, a nie 5, nie wiem dlaczego. Jeśli jest jakiś sposób instalacji piątego xcode - proszę o pomoc). Poszedłem więc na stronę programistów Apple i nie znalazłem narzędzi wiersza poleceń dla 10.9. Próbowałem za 10.8 - wypisuje „Spróbuj zainstalować na 10.7”, po wypróbowaniu z narzędziami na 10.7 - drukuje „spróbuj za 10.8”.

Proszę pomóż. Podam wszystkie informacje o pomocy.