title: Missing ruby.h header when installing Command-T
body: <p>I am attempting to install Command-T on OS X 10.8 and have followed the instructions on <a href="http://www.vim.org/scripts/script.php?script_id=3025" rel="nofollow">http://www.vim.org/scripts/script.php?script_id=3025</a>, however when I try to build the Makefile I get the following error:</p>
  
  <pre><code>Command-T[master+]/ruby/command-t
   ❯ ruby extconf.rb
  checking for ruby.h... no
  couldn't find ruby.h (required)
  </code></pre>
  
  <p>I am using system ruby, which is the one Vim was compiled (by myself) against. As you can see, Vim is compiled with ruby support:</p>
  
  <pre><code>Command-T[master+]/ruby/command-t
   ❯ ruby --version
  ruby 1.8.7 (2012-02-08 patchlevel 358) [universal-darwin12.0]
  
  Command-T[master+]/ruby/command-t
   ❯ vim --version
  VIM - Vi IMproved 7.3 (2010 Aug 15, compiled Jan 29 2013 10:09:48)
  MacOS X (unix) version
  Included patches: 1-785
  Compiled by caleb@sirius.local
  Huge version without GUI.  Features included (+) or not (-):
  +arabic +autocmd -balloon_eval -browse ++builtin_terms +byte_offset +cindent 
  -clientserver +clipboard +cmdline_compl +cmdline_hist +cmdline_info +comments 
  +conceal +cryptv +cscope +cursorbind +cursorshape +dialog_con +diff +digraphs 
  -dnd -ebcdic +emacs_tags +eval +ex_extra +extra_search +farsi +file_in_path 
  +find_in_path +float +folding -footer +fork() -gettext -hangul_input +iconv 
  +insert_expand +jumplist +keymap +langmap +libcall +linebreak +lispindent 
  +listcmds +localmap -lua +menu +mksession +modify_fname +mouse -mouseshape 
  +mouse_dec -mouse_gpm -mouse_jsbterm +mouse_netterm +mouse_sgr -mouse_sysmouse 
  +mouse_urxvt +mouse_xterm +multi_byte +multi_lang -mzscheme +netbeans_intg 
  +path_extra -perl +persistent_undo +postscript +printer +profile +python 
  -python3 +quickfix +reltime +rightleft +ruby +scrollbind +signs +smartindent 
  -sniff +startuptime +statusline -sun_workshop +syntax +tag_binary 
  +tag_old_static -tag_any_white -tcl +terminfo +termresponse +textobjects +title
   -toolbar +user_commands +vertsplit +virtualedit +visual +visualextra +viminfo 
  +vreplace +wildignore +wildmenu +windows +writebackup -X11 -xfontset -xim -xsmp
   -xterm_clipboard -xterm_save 
     system vimrc file: "$VIM/vimrc"
       user vimrc file: "$HOME/.vimrc"
        user exrc file: "$HOME/.exrc"
    fall-back for $VIM: "/usr/local/share/vim"
  Compilation: /usr/bin/clang -c -I. -Iproto -DHAVE_CONFIG_H   -DMACOS_X_UNIX -no-cpp-precomp  -Os -w -pipe -march=native -Qunused-arguments -mmacosx-version-min=10.8 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1      
  Linking: /usr/bin/clang   -L.    -L/usr/local/lib -o vim       -lm  -lncurses -liconv -framework Cocoa     -framework Python   -lruby -lobjc 
  </code></pre>
  
  <p>From Vim:</p>
  
  <pre><code>:ruby puts RUBY_VERSION
  1.8.7
  </code></pre>
  
  <p>I've located the <code>ruby.h</code> file needed in /System/Library/Frameworks/Ruby.framework/Versions/1.8/Headers/ruby.h and have tried both</p>
  
  <pre><code>export CPP_INCLUDE_PATH=/System/Library/Frameworks/Ruby.framework/Versions/1.8/Headers/
  export C_INCLUDE_PATH=/System/Library/Frameworks/Ruby.framework/Versions/1.8/Headers/
  </code></pre>
  
  <p>but neither of those make <code>have_header('ruby.h')</code> return true, and <code>ruby extconf.rb</code> continues to fail.</p>
  
  <p>Any ideas?</p>