When running the gem install sqlite3 command on Mac OS X I experience the following error message:
    Users-MacBook-Pro:~ user$ gem install sqlite3
Building native extensions.  This could take a while...
ERROR:  Error installing sqlite3:
    ERROR: Failed to build gem native extension.
    /Users/user/.rvm/rubies/ruby-2.1.2/bin/ruby extconf.rb
checking for sqlite3.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=/Users/user/.rvm/rubies/ruby-2.1.2/bin/ruby
    --with-sqlite3-dir
    --without-sqlite3-dir
    --with-sqlite3-include
    --without-sqlite3-include=${sqlite3-dir}/include
    --with-sqlite3-lib
    --without-sqlite3-lib=${sqlite3-dir}/lib
    --enable-local
    --disable-local
/Users/user/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/mkmf.rb:456:in `try_do': The compiler failed to generate an executable file. (RuntimeError)
You have to install development tools first.
    from /Users/user/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/mkmf.rb:587:in `try_cpp'
    from /Users/user/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/mkmf.rb:1120:in `block in find_header'
    from /Users/user/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/mkmf.rb:918:in `block in checking_for'
    from /Users/user/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/mkmf.rb:351:in `block (2 levels) in postpone'
    from /Users/user/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/mkmf.rb:321:in `open'
    from /Users/user/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/mkmf.rb:351:in `block in postpone'
    from /Users/user/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/mkmf.rb:321:in `open'
    from /Users/user/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/mkmf.rb:347:in `postpone'
    from /Users/user/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/mkmf.rb:917:in `checking_for'
    from /Users/user/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/mkmf.rb:1119:in `find_header'
    from extconf.rb:35:in `<main>'
extconf failed, exit code 1
Gem files will remain installed in /Users/user/.rvm/gems/ruby-2.1.2/gems/sqlite3-1.3.9 for inspection.
Results logged to /Users/user/.rvm/gems/ruby-2.1.2/extensions/x86_64-darwin-13/2.1.0-static/sqlite3-1.3.9/gem_make.out
Users-MacBook-Pro:~ user$ 
I am relatively new to using the terminal, ruby on rails and ruby gems and have been scratching my head (i.e. searching google) for a few hours now, any help would be greatly appreciated. Have tried the sudo command but no luck there.
 
     
    